The shear viscosities of l3 silicate liquids along the NarSiOr-TiO, and CaSiOr-TiO, joins as well as six liquids based on the sphene stoichiometry X#TiSiO. (where X represents Li, Na, K, Rb, Cs, Ca, and Sr) have been measured in equilibrium with air using the concentric cylinder method. The NarSiOr-TiO, join was investigated from l0 to 50 mol0/oT iO, in the temperaturer ange 1000-1150 "C, whereast he CaSiO3-TiO,jo in was investigated from l0 to 80 molo/oT iO, in the temperature range of 1400-1625' C. The shear viscosities of liquids in the CaSiOr-TiO, and NarSiOr-TiO2 systems decrease with the addition of TiO,. The decreaseis linear in the CaSiOr-TiO, system at 1400- I 600 'C but nonlinear in the NarSiO3-TiO, system at 1000-1 150'C. Viscosities of melts of sphene stoichiometry, X1;TiSiO, (where X: Cs, Rb, K, Na, Li, Ba, Sr, and Ca), decrease with increasing field strength. Similar to the behavior of ferro-, alumino-, and galliosilicate
melts, this decreaseis strong for the alkalies but very weak for the alkaline earths

Dingwell, Donald B.

English

Open Access LMU

American Mineralogist, Volume 77, pages 270-274, 1992Shear viscosity of alkali and alkaline earth titanium silicate liquidsDoN.qlo B. DrNcwnr,r,Bayerisches Geoinstitut, Universitiit Bayreuth, Postfach l0 12 51, W8580 Bayreuth, GermanyAnsrnlcrThe shear viscosities of l3 silicate liquids along the NarSiOr-TiO, and CaSiOr-TiO,joins as well as six liquids based on the sphene stoichiometry X#TiSiO. (where X rep-resents Li, Na, K, Rb, Cs, Ca, and Sr) have been measured in equilibrium with air usingthe concentric cylinder method. The NarSiOr-TiO, join was investigated from l0 to 50mol0/o TiO, in the temperature range 1000-1150 "C, whereas the CaSiO3-TiO, join wasinvestigated from l0 to 80 molo/o TiO, in the temperature range of 1400-1625 'C.The shear viscosities of liquids in the CaSiOr-TiO, and NarSiOr-TiO2 systems decreasewith the addition of TiO,. The decrease is linear in the CaSiOr-TiO, system at 1400- I 600'C but nonlinear in the NarSiO3-TiO, system at 1000-1 150'C. Viscosities of melts ofsphene stoichiometry, X1;TiSiO, (where X: Cs, Rb, K, Na, Li, Ba, Sr, and Ca), decreasewith increasing field strength. Similar to the behavior of ferro-, alumino-, and galliosilicatemelts, this decrease is strong for the alkalies but very weak for the alkaline earths.INrnonucrroN melts. The systems NarSiOr-TiO, and CaSiO.-TiO, wereTio, is present in major element amounts in most chosenJor this investigation to test for the contrastingigneous rocks. Although 2-3 wto/o TiO, is the averag" t*:t.:f alkalies and alkaline earths on the coordinationvalue for cenozoic alkali basalts and basanites (chayes, of rtQa in silicate melts'1975), much higher concentrations are found in 't otcattic . Additionally, a series of alkali and alkaline earth tita-rocks of the poiassic-ultrapotassic series (Gunter et al., nium silicate liquids of Xi;TiSiO, stoichiometry were1990). Foley and Wheller (1990) report values up to 9 chosen to evaluate the effect of exchanges on melt vis-wto/o TiO, from some lamproites, and Mitchell 1t ll t I tras cosity. Density determinations for all of these liquids areanalyzedglass inclusions in volcanic sanidine from ihese presented in a companion paper (Dingwell, in prepara-rocks containing up to I I wto/o TiOr. Although such ex- tlon)'amples are not very widespread, the unusual geochem-istry of these lamproites and continuing discussions of Mnrrrontheir petrogenesis make the investigation of the TiO, The primary joins chosen for this investigation of meltcomponent in silicate melts timely for geochemists. viscosity and the density investigation of Dingwell (inThe glass literature is often an abundant source of in- preparation) are the metasilicate-TiO, joins, CaSiOr-TiO,formation on the frozen remains of high-temperature sil- and NarSiO3-TiOr, and melts of the stoichiometryicate liquids. Analysis of the quench-rate dependence of XikTlSlOs (where X: Ca, Sr, Ba, Li, Na, K, Rb, Cs).glass properties opens a window into the temperature de- The starting materials for these viscosity determinationspendence of liquid properties (Dingwell and Webb, 1989, were CaCO. (99.5), SrCOj, BaCOr, Li,CO3, NarCO, (99.9),1990). Crystal-free, Ti-bearing glasses are, however, dif- &COr, Rb,CO3 (99), CsrCOr, TiO, (99.8), and SiO' (99.5).ficult to obtain, and this difficulty may have contributed The starting oxides and carbonates were dried at 120'Cto some of the controversy surrounding the structural role for 24 h prior to weighing. Powder mixtures of the car-of TiO, in silicate glasses and, by extrapolation, liquids bonates and oxides were weighed into plastic bottles in(see Mysen, 1988, for a review). batches equivalent to 100 g of decarbonated material.Thus, in an attempt to evaluate directly the effects of The powders were mixed by agitation for approximatelyTiO, on the physical properties of silicate liquids, the 5 min. The mixed powders were melted stepwise in 75-density (Dingwell, 199 I, and in preparation) and viscos- cm3 Pt crucibles in an MoSi, box furnace. The Na-bearingity (this study) of a series of alkali and alkaline earth batches were melted at I 150 'C to minimize Na volatil-silicate liquids have been investigated. ization in these fluid melts, whereas the Ca-bearing batchesIn a more general sense, the investigation of physical were melted directly at 1600 "C. The Rb-, Cs-, andproperties of TiOr-bearing melts provides an indication K-bearing batches were melted at 1000 "C, whereas theof the type of effects that variable coordination number Li-, Ba-, and Sr-bearing batches were melted at 1650'C.for any component may have on the behavior of silicate Each melt was poured from the Pt crucible onto a stain-ooo3-004x/92/0304-0270s02.00 270DINGWELL: SHEAR VISCOSITY OF SILICATE LIQUIDSTABLE 1A. Glass analyses by electron microprobeSample XOIX2O TiO, SiO,27rless steel plate for cooling. The Na-bearing liquids cooledto transparent, colorless glasses, whereas the Ca-bearingliquids cooled to partly crystalline samples. SubsequentX-ray diffraction investigation of the Na-bearing "glass-es" revealed a broad peak indicating poorly crystalline orfine-grained NarTiSiO, crystals. Subsequent dropquenches of the Na,TiSiO, liquid into H,O yielded glass-es with identical X-ray diffraction results. Because of thiscryptocrystallinity, no investigations of supercooled liq-uid viscosity or density were attempted, and the data pre-sented here were obtained at superliquidus temperatures.After the viscometry experiments, the chemical com-positions of glassy fragments of the quenched sampleswere determined using the electron microprobe. The re-sults and analysis conditions are included in Table la.The K, Rb, and Cs glasses were extremely hygroscopic,and the Li melt crystallized fully. Therefore, neither couldbe analyzed by microprobe. These samples were analyzedusing solution-based ICP-AES methods. The results andmethods are described in Table lb. The results Oable l)confirm the stoichiometric compositions of all the melts.The shear viscosities of the liquids were determinedusing the concentric cylinder method at I atm in equilib-rium with air. The temperature ranges for the Na-bearingand Ca-bearing liquids were 950-l 150 .C and 1400-1600'C, respectively. The viscosities were measured with aBrookfield LVTD head (full-scale torque : f.g x lQ 3Nt m) and rotation speeds of 50 or 100 rpm. This studyused the crucible and low-viscosity spindle design ofDingwell and Virgo (1988). The furnace, viscometer as-sembly, and computer interface as well as the operatingmethod and calibration are described by Dingwell (1989a,1990). The viscosities measured are relative. The instru-ment has been calibrated most recently by standard glassDGG-I available from the Deutsche Glastechnische Ge-sellschaft. The viscosity data are accurate to +50/o at lo.Newtonian rheology was observed over the limited dy-namic range of these measurements (approximately 0.3log,o units). This result is consistent with the fact that thecalculated relaxation times for shear in these liquids usingthe Maxwell approximation (Dingwell and Webb, 1989,1990) and the Newtonian viscosity data from this studyare several log,o units lower than the experimental strainrates. We appear to be observing relaxed viscosities of aliquid.After the viscometry was completed, each sample wasremoved from the furnace, reheated at I 150 or 1600 "Cin an MoSi, box furnace, and removed quickly from thatfurnace to be poured once more onto the stainless steelplate. The crucible was cleaned in HF and used for thenext sample.Rrsur-rs AND DrscussroNThe results of the viscosity determinations are pre-sented in Table 2. The viscosities of all the Na-bearingliquids lie in the range of log,o a : |.2-0.1 in the I 150-1000 "C temperature range, whereas those of the Ca-bear-ing liquids lie in the range of log,o 4 : 0.5 to -0.5 for theNTSlNTS2NTSSNTS4NTS5CTSlCTS2CTS3CTS4CTS5CTS6STSSBTS546.06(0.14r.42.54(0.10)39.37(0.20)33.98(0.1 6)29.33(0.1 0)45.36(0.21)41.12(0.10)37.60(0.30)33.82(0.17)28.98(0.13)24.24(0.0e)43.08(0.43)48.48(0.3e)8.20(0.1 7)15.54(0.1 5)23.'t3(0.12)32.29(0 .11)40.88(0.13)7.70(0.15)16.40(0.62)22.80(0.14)30.76(0.42)40.38(0.15)50.12(0.20)32.64(0.20)27.46(0.45)45.74 91.89'.(0.5s)41.93 96.17(0.37)37.50 97.46(0.16)33.73 98.13(0.12)29.78 97.83(0.14)46.94 98.20(o.22142.49 96.1710.24139.61 98.49(0.26)35.38 98.57(0.35)30.66 98.62(0.20)25.65 99.43(0.12)24.66 100.38(0.40)22.54 98.48(0.32)Note.' Microprobe analyses obtained using wavelength dispersive anal-ysis on a Cameca SX 50 instrument. Operating conditions 15 kV accel-erating voltage, 15 nA current on brass, a 10 x 10 pm spot, and 20 scounting times. Standards are albite (Na), wollastonite (Ca, Si), and MnTiO3(Ti) and synthetic glasses BFS1 (Ba) and SFS1 (Sr). Data are plotted inFigure 1.' Low total due to H,O absorption; analyses are averages of ten spots,normalized to 100o/".*. Numbers in brackets arc 16 ot multiple analyses.temperature range 1400-1600 "C. The Xi;TiSiO, liquidsrange in log,o viscosity from -0.6 to 2.6. The viscosity-temperature relationships of the liquids are presented inFigures la and lb, and the composition dependence isillustrated in Figures 2a and,2b. The temperature depen-dence ofthe viscosity can be described usinglogro4:  a + b/Twhere a and b are constants. Table 3 contains the valuesof a and b obtained for these liquids. The temperaturedependence of viscosity decreases lightly with increasingTiO, content.The composition dependence of viscosity is plotted asa series of isotherms in Figures 2a and 2b. Viscosity is aTABLE 18. Sample analyses by ICP-AESxolx2o Tio, sio,LTS5NTSSKTS5RTS5CsTS517.630.5(s)39.9(1)57(2167(4)47.0(1)39.6(1 )34.s(2)24.7(4)19.6(7)35.9(4) 100.529.2(11 99.324.8(31 99.618.0(1) 99.714.4(21 101 .0Note.'Analyses by inductively coupled atomic emission spectroscopyusing an HBF4/HF dissolution of glasses and mixed, single-element stan-dard solutions. Performed on a sequential JY 24 spectrometer trom In-struments S.A. Numbers in parantheses represent 1o.272 DINGWELL: SHEAR VISCOSITY OF SILICATE LIQUIDS1 21 10 10 5o 41 2'I 11 0o 90 80 . 60 5o 40 3o 20 10 5o 4a)Ga!=aooo)o1 0A  0 e6( !  n aE  - -5  o to8  0 6o>  0 5I  ^ .0 . 3o 27 4  7 610,0o0/r(K)Mol % TiO,20407 A0 3A  6 26  - -(LI  o 1' 6 0^ 0 3af  o zi o roO  d no  - -oo)5  3  5 . 5  5 . 7  s . 91O,O00/T(K)Fig. l. Viscosity-temperature relationships of liquids on the(a) Na,SiO.-TiO, and (b) CaSiO.-TiO, joins.linear function of composition in the CaSiOr-TiO, sys-tem, whereas there is a slight negative deviation fromadditivity in the NarSiOr-TiO, system. The Na,SiOr-TiO,data of Figure la extrapolate to values in good agreementTABLE 2A. Viscosity determinations (NTS and CTS)- o 4- 0 510 20 30 40 50 60Mol % TiO,Fig.  2.  Viscosi ty-cornposi t ion re lat ionships on the (a)NarSiOr-TiO, and (b) CaSiO, joins.with those obtained by Bockris et al. (1955) on NarSiO,liquid, and the data from the CaSiO3-TiO, join (Fig. lb)agree well with the viscosity data of Bockris and Lowe(1954) and Urbain et al. (1982).- o 3- o 4- 0 5Viscosity (dPaS)Temp.("c) CTSO CTS1 CTS2 CTS3 CTS4 CTSs CTS6 CTST CTSS15941 569154415201 4951471144614211 3972.O4 1.671.822.O72.382.761 .211.341 .511 .721 .972.270.8800.9831 . 1 01.251.421.631.892.212.600.6380.7210.7810.8780.9871 . 1 21.281.491.74o.4970.5350.5830.u70.7240.814o.9241.061.23o.3440.3730.4040.4430.4910.5500.620o.7150.809o.223o.2750.333NTSl NTS21 15111261't02107710521 02810039784.945.486.628.019.7812.914.53.474.004.705.566.618 .109.451 1 . 62.2'l2.552.943.414.004.661 .662 .152.492.933.481 .271.451.681 .962.332-80/Votej Viscosity data are accurate to +5% at 2o. Note that these values are in dPaS, not in log,o units.DINGWELL: SHEAR VISCOSITY OF SILICATE LIQUIDS 2732 . 62 . 2{/nrisiouTABLE 3. Arrhenius parametersSample 5 x 1 @Numberof data: 1 8(L9 t +R  r noot o 6-  o . 2CTSlCTS2CTS3cTs4CTS5CTS6NTSlNTS2NTS3NTS4NTSSCsTS5RTS5KTS5BTSSSTS5LTS5-3.730(0.009)-3.80s(0.005)-4.052(0.006)-3.877(0.008)3.678(0.010)-3.644(0.010)-3.613(0.01 9)-3.307(0.005)-3.185(0 005)-3.393(0.004)-3.762(0.01 1)-3.983(0.019)-4.141(0.030)-3.140(0.004)-4.031(0.028)-3 684(0.01s)-2.841(0.011)7.367(0.037)7.249(0.016)7.444(0.010)6.859(0.013)6.270(0.016)5.914(0.01 5)6.1 07(0.026)s 472(0.005)5.022(0.004)5.1 1 9(0.00s)5.485(0.010)6.343(0.663)6.701 (0.1 24)5.1 66(0.004)6.948(0.237)6.343(0.444)4.233(0.1 30)569III1 0eo1 191 341 1- o 2- o 67 810,000/r(K)Fig. 3. Viscosity-temperature relationships for melts of thestoichiometry Xi;TiSiO5.Figure 3 illustrates the viscosity-temperature relation-ships of the liquids of sphene stoichiometry. The alkalineearth liquids cluster tightly with a slight decrease fromBa > Sr > Ca. Similar results have been observed for thealkaline earth galliosilicates (Dingwell, 1990; Balewick andShelby, 1990), aluminosilicates (Urbain et al., 1982), andferrosil icates (Dingwell, 1989b). The relative fieldTABLE 28. Viscosity determinations (XTSs)Note.' Numbers in parentheses are standard errors on the linear regres-sions. Not to be used for extrapolation of temperature-viscosity relation-shios.strengths of the alkaline earth cations have a structuralinfluence on these liquids whose effect for viscosity tran-scends the identity of the third cation (Ti, Al, Ga, or Fe).The shear viscosity ofthe alkali titanosilicates ofsphenestoichiometry is more sensitive to cation identity. The1 0Viscosity (dPaS)Temp. ("C) RTS5 KTSS LTS5 BTS5 CTS51 6251 5941 569154415201 4951471144614211 3971 3781 34813231298127312491  1 5 11  126110210771 0521 0281 0039789s492590087585082580077575016.226.346.889.11 5 113 .517 .O21.426.936.347.967.691.21351702823.083.584 .164.85s.706.788 .11o E o12.O1 .271.451 .681 .962.332.800.2500.2680.2910.3040.3270.3530.381o 407o.4470.4900.5590.6700.7380.8170.9010.9931 . 1 21.301.501.752.062.473.013.690.695o.4970.5350.583o.647o.7240.8140.9241.061.23o.4670.563/Vofe.-Viscosity data are accurate to +57" at 2o. Note that these values are in dPaS, not in loglo units.274viscosity decreases 0.6 log,o units with alkali substitutionfrom Cs to Na. Data for the Li composition are insuffi-cient to distinguish the trend further. The general behav-ior of the alkali titanosilicates matches again that of theequivalent gallio-, alumino-, and ferrosilicate liquids.One apparent contrast to the trends observed for gal-lio-, ferro-, and aluminosilicate liquids is the observationthat the alkali titanium silicates have lower viscositiesthan the alkaline earth titanium silicate liquids. In a com-panion study, the densities of all of the investigated liq-uids have been determined (Dingwell, in preparation).The partial molar volume of TiO, has been computed foreach of the liquids of sphene stoichiometry. The partialmolar volume of TiO, is alkali-cation specific. In general,much larger values are observed for the alkali vs. thealkaline earth titanium silicates and pure TiO, liquid(Dingwell, 1991), suggesting that Ti has a lower coordi-nation number in the alkali titanium silicates. The ap-parent shift in coordination number of Ti in the alkalititanium silicate liquids may be responsible for the lowerviscosity observed for the alkali silicate vs. the alkalineearth silicate liquids.AcrNowr,rocMENTSI thank DedefKrau8e and Kurt Klasinski for technical assisrance, CharlesRoss II for X-ray diffraction work, and Anna Dietel for ICP-AES analysesRrrpnpNcns crrEDBalewick, L.A., and Shelby, J.S. (1990) Properties ofcalcium, strontiumand barium galliosilicate glasses Journal of the American Ceramic So-ciety, 73, 213-216.Bockris, J.O'M., and Lowe, D.L. (1954) Viscosity and structure of moltensilicates. Proceedings ofthe Royal Society ofLondon, A226,423-435.Bockris, J O'M., MacKenzie, K.D., and Kitchener, J.A. (1955) ViscousDINGWELL: SHEAR VISCOSITY OF SILICATE LIQUIDSflow in silica and binary silicate liquids. Transactions of the FaradaySociety, 51, 1734-1748Chayes, F. (1975) Statistical petrology. Carnegie Institution ofWashing-ton Year Book.74. 542-550.Dingwell, D.B. (l 989a) The effect of fluorine on the viscosity of diopsideliquid. American Mineralogist, 7 4, 333-338.-(1989b) Shear viscosities of ferrosilicate liquids. American Min-eralogist, 7 4, 1038-1044.-(1990) Shear viscosities of galliosilicate liquids. American Min-eralogist, 7 5, 123l-1237.-(1991) The density of liquid TiO,. Journal of the American Ce-ramic Society, 74, 27 18-27 19.Dingwell, D.B., and Virgo, D. (1988) Viscosities of melts in the NarO-FeO-FerOr-SiO, system and factors controlling relative viscosities offully polymerized silicate melts. Geochimica et Cosmochimica Acta,52,395-403.Dingwell, D.B., and Webb, S.L. (1989) Structural relaxation in silicatemelts and non-NeMonian melt rheology in geological processes. Phys-ics and Chemistry of Minerals, 16, 508-516.-(1990) Relaxation in silicate melts. European Journal of Miner-alogy, 2, 427 -449 .Foley, S.F., and Wheller, G.E. (1990) Parallels in the origin of the geo-chemical signatures of island arc volcanics and continental potassicigneous rocks: The role ofresidual titanites Chemical Geology, 85, l-I EGunter, W.D., Hoinkes, G., Ogden, P., and Pajari, P.E. (1990) Origin ofleucite-rich and sanidine-rich flow layers in the lrucite Hills VolcanicField, Wyoming. Journal of Geophysical Research, 95, I 59 I l- I 5928.Mitchell, R.H. (1991) Coexisting glasses occurring as inclusions in leucitefrom laproites: Examples of silicate liquid immiscibility in ultrapotassicmagmas. Mineralogical Magazine, 55, 197 -2O2.Mysen, B.O. (1988) Structure and properties ofsilicate melts, 354 p. El-sevier, Amsterdam.Urbain, G., Bottinga, Y., and Richet, P (1982) Viscosity of liquid silica,silicates and alumino-silicates. Geochimica et Cosmochimica Acta, 46,106t-1072.Mnxuscprm rucErwD Aucusr 12, l99lMeNuscnryr AccEprED Noveusrn 5. l99l

Shear viscosity of alkali and alkaline earth titanium silicate liquids

Universität München: Elektronischen Publikationen

American Mineralogist, Volume 77, pages 270-274, 1992
Shear viscosity of alkali and alkaline earth titanium silicate liquids
DoN.qlo B. DrNcwnr,r,
Bayerisches Geoinstitut, Universitiit Bayreuth, Postfach l0 12 51, W8580 Bayreuth, Germany
Ansrnlcr
The shear viscosities of l3 silicate liquids along the NarSiOr-TiO, and CaSiOr-TiO,
joins as well as six liquids based on the sphene stoichiometry X#TiSiO. (where X rep-
resents Li, Na, K, Rb, Cs, Ca, and Sr) have been measured in equilibrium with air using
the concentric cylinder method. The NarSiOr-TiO, join was investigated from l0 to 50
mol0/o TiO, in the temperature range 1000-1150 "C, whereas the CaSiO3-TiO, join was
investigated from l0 to 80 molo/o TiO, in the temperature range of 1400-1625 'C.
The shear viscosities of liquids in the CaSiOr-TiO, and NarSiOr-TiO2 systems decrease
with the addition of TiO,. The decrease is linear in the CaSiOr-TiO, system at 1400- I 600
'C but nonlinear in the NarSiO3-TiO, system at 1000-1 150'C. Viscosities of melts of
sphene stoichiometry, X1;TiSiO, (where X: Cs, Rb, K, Na, Li, Ba, Sr, and Ca), decrease
with increasing field strength. Similar to the behavior of ferro-, alumino-, and galliosilicate
melts, this decrease is strong for the alkalies but very weak for the alkaline earths.
INrnonucrroN melts. The systems NarSiOr-TiO, and CaSiO.-TiO, were
Tio, is present in major element amounts in most chosenJor this investigation to test for the contrasting
igneous rocks. Although 2-3 wto/o TiO, is the averag" t*:t.:f alkalies and alkaline earths on the coordination
value for cenozoic alkali basalts and basanites (chayes, of rtQa in silicate melts'
1975), much higher concentrations are found in 't otcattic . 
Additionally, a series of alkali and alkaline earth tita-
rocks of the poiassic-ultrapotassic series (Gunter et al., nium silicate liquids of Xi;TiSiO, stoichiometry were
1990). Foley and Wheller (1990) report values up to 9 chosen to evaluate the effect of exchanges on melt vis-
wto/o TiO, from some lamproites, and Mitchell 1t ll t I tras cosity. 
Density determinations for all of these liquids are
analyzedglass inclusions in volcanic sanidine from ihese presented in a companion paper (Dingwell, in 
prepara-
rocks containing up to I I wto/o TiOr. Although such ex- tlon)'
amples are not very widespread, the unusual geochem-
istry of these lamproites and continuing discussions of Mnrrron
their petrogenesis make the investigation of the TiO, The primary joins chosen for this investigation of melt
component in silicate melts timely for geochemists. viscosity and the density investigation of Dingwell (in
The glass literature is often an abundant source of in- preparation) are the metasilicate-TiO, joins, CaSiOr-TiO,
formation on the frozen remains of high-temperature sil- and NarSiO3-TiOr, and melts of the stoichiometry
icate liquids. Analysis of the quench-rate dependence of XikTlSlOs (where X: Ca, Sr, Ba, Li, Na, K, Rb, Cs).
glass properties opens a window into the temperature de- The starting materials for these viscosity determinations
pendence of liquid properties (Dingwell and Webb, 1989, were CaCO. (99.5), SrCOj, BaCOr, Li,CO3, NarCO, (99.9),
1990). Crystal-free, Ti-bearing glasses are, however, dif- &COr, Rb,CO3 (99), CsrCOr, TiO, (99.8), and SiO' (99.5).
ficult to obtain, and this difficulty may have contributed The starting oxides and carbonates were dried at 120'C
to some of the controversy surrounding the structural role for 24 h prior to weighing. Powder mixtures of the car-
of TiO, in silicate glasses and, by extrapolation, liquids bonates and oxides were weighed into plastic bottles in
(see Mysen, 1988, for a review). batches equivalent to 100 g of decarbonated material.
Thus, in an attempt to evaluate directly the effects of The powders were mixed by agitation for approximately
TiO, on the physical properties of silicate liquids, the 5 min. The mixed powders were melted stepwise in 75-
density (Dingwell, 199 I, and in preparation) and viscos- cm3 Pt crucibles in an MoSi, box furnace. The Na-bearing
ity (this study) of a series of alkali and alkaline earth batches were melted at I 150 'C to minimize Na volatil-
silicate liquids have been investigated. ization in these fluid melts, whereas the Ca-bearing batches
In a more general sense, the investigation of physical were melted directly at 1600 "C. The Rb-, Cs-, and
properties of TiOr-bearing melts provides an indication K-bearing batches were melted at 1000 "C, whereas the
of the type of effects that variable coordination number Li-, Ba-, and Sr-bearing batches were melted at 1650'C.
for any component may have on the behavior of silicate Each melt was poured from the Pt crucible onto a stain-
ooo3-004x/92/0304-0270s02.00 270
DINGWELL: SHEAR VISCOSITY OF SILICATE LIQUIDS
TABLE 1A. Glass analyses by electron microprobe
Sample XOIX2O TiO, SiO,
27r
less steel plate for cooling. The Na-bearing liquids cooled
to transparent, colorless glasses, whereas the Ca-bearing
liquids cooled to partly crystalline samples. Subsequent
X-ray diffraction investigation of the Na-bearing "glass-
es" revealed a broad peak indicating poorly crystalline or
fine-grained NarTiSiO, crystals. Subsequent drop
quenches of the Na,TiSiO, liquid into H,O yielded glass-
es with identical X-ray diffraction results. Because of this
cryptocrystallinity, no investigations of supercooled liq-
uid viscosity or density were attempted, and the data pre-
sented here were obtained at superliquidus temperatures.
After the viscometry experiments, the chemical com-
positions of glassy fragments of the quenched samples
were determined using the electron microprobe. The re-
sults and analysis conditions are included in Table la.
The K, Rb, and Cs glasses were extremely hygroscopic,
and the Li melt crystallized fully. Therefore, neither could
be analyzed by microprobe. These samples were analyzed
using solution-based ICP-AES methods. The results and
methods are described in Table lb. The results Oable l)
confirm the stoichiometric compositions of all the melts.
The shear viscosities of the liquids were determined
using the concentric cylinder method at I atm in equilib-
rium with air. The temperature ranges for the Na-bearing
and Ca-bearing liquids were 950-l 150 .C and 1400-1600
'C, respectively. The viscosities were measured with a
Brookfield LVTD head (full-scale torque : f.g x lQ 3
Nt m) and rotation speeds of 50 or 100 rpm. This study
used the crucible and low-viscosity spindle design of
Dingwell and Virgo (1988). The furnace, viscometer as-
sembly, and computer interface as well as the operating
method and calibration are described by Dingwell (1989a,
1990). The viscosities measured are relative. The instru-
ment has been calibrated most recently by standard glass
DGG-I available from the Deutsche Glastechnische Ge-
sellschaft. The viscosity data are accurate to +50/o at lo.
Newtonian rheology was observed over the limited dy-
namic range of these measurements (approximately 0.3
log,o units). This result is consistent with the fact that the
calculated relaxation times for shear in these liquids using
the Maxwell approximation (Dingwell and Webb, 1989,
1990) and the Newtonian viscosity data from this study
are several log,o units lower than the experimental strain
rates. We appear to be observing relaxed viscosities of a
liquid.
After the viscometry was completed, each sample was
removed from the furnace, reheated at I 150 or 1600 "C
in an MoSi, box furnace, and removed quickly from that
furnace to be poured once more onto the stainless steel
plate. The crucible was cleaned in HF and used for the
next sample.
Rrsur-rs AND DrscussroN
The results of the viscosity determinations are pre-
sented in Table 2. The viscosities of all the Na-bearing
liquids lie in the range of log,o a : |.2-0.1 in the I 150-
1000 "C temperature range, whereas those of the Ca-bear-
ing liquids lie in the range of log,o 4 : 0.5 to -0.5 for the
NTSl
NTS2
NTSS
NTS4
NTS5
CTSl
CTS2
CTS3
CTS4
CTS5
CTS6
STSS
BTS5
46.06
(0.14r.
42.54
(0.10)
39.37
(0.20)
33.98
(0.1 6)
29.33
(0.1 0)
45.36
(0.21)
41.12
(0.10)
37.60
(0.30)
33.82
(0.17)
28.98
(0.13)
24.24
(0.0e)
43.08
(0.43)
48.48
(0.3e)
8.20
(0.1 7)
15.54
(0.1 5)
23.'t3
(0.12)
32.29
(0 .11)
40.88
(0.13)
7.70
(0.15)
16.40
(0.62)
22.80
(0.14)
30.76
(0.42)
40.38
(0.15)
50.12
(0.20)
32.64
(0.20)
27.46
(0.45)
45.74 91.89'.
(0.5s)
41.93 96.17
(0.37)
37.50 97.46
(0.16)
33.73 98.13
(0.12)
29.78 97.83
(0.14)
46.94 98.20
(o.221
42.49 96.17
10.241
39.61 98.49
(0.26)
35.38 98.57
(0.35)
30.66 98.62
(0.20)
25.65 99.43
(0.12)
24.66 100.38
(0.40)
22.54 98.48
(0.32)
Note.' Microprobe analyses obtained using wavelength dispersive anal-
ysis on a Cameca SX 50 instrument. Operating conditions 15 kV accel-
erating voltage, 15 nA current on brass, a 10 x 10 pm spot, and 20 s
counting times. Standards are albite (Na), wollastonite (Ca, Si), and MnTiO3
(Ti) and synthetic glasses BFS1 (Ba) and SFS1 (Sr). Data are plotted in
Figure 1.
' Low total due to H,O absorption; analyses are averages of ten spots,
normalized to 100o/".
*. Numbers in brackets arc 16 ot multiple analyses.
temperature range 1400-1600 "C. The Xi;TiSiO, liquids
range in log,o viscosity from -0.6 to 2.6. The viscosity-
temperature relationships of the liquids are presented in
Figures la and lb, and the composition dependence is
illustrated in Figures 2a and,2b. The temperature depen-
dence ofthe viscosity can be described using
logro4:  a + b/T
where a and b are constants. Table 3 contains the values
of a and b obtained for these liquids. The temperature
dependence of viscosity decreases lightly with increasing
TiO, content.
The composition dependence of viscosity is plotted as
a series of isotherms in Figures 2a and 2b. Viscosity is a
TABLE 18. Sample analyses by ICP-AES
xolx2o Tio, sio,
LTS5
NTSS
KTS5
RTS5
CsTS5
17.6
30.5(s)
39.9(1)
57(21
67(4)
47.0(1)
39.6(1 )
34.s(2)
24.7(4)
19.6(7)
35.9(4) 100.5
29.2(11 99.3
24.8(31 99.6
18.0(1) 99.7
14.4(21 101 .0
Note.'Analyses by inductively coupled atomic emission spectroscopy
using an HBF4/HF dissolution of glasses and mixed, single-element stan-
dard solutions. Performed on a sequential JY 24 spectrometer trom In-
struments S.A. Numbers in parantheses represent 1o.
272 DINGWELL: SHEAR VISCOSITY OF SILICATE LIQUIDS
1 2
1 1
0 1
0 5
o 4
1 2
'I 1
1 0
o 9
0 8
0 . 6
0 5
o 4
0 3
o 2
0 1
0 5
o 4
a)
G
a!
=
a
o
o
o)
o
1 0
A  0 e
6
( !  n a
E  - -
5  o t
o
8  0 6
o
>  0 5
I  ^ .
0 . 3
o 2
7 4  7 6
10,0o0/r(K)
Mol % TiO,
20
40
7 A
0 3
A  6 2
6  - -
(L
I  o 1
' 6 0
^ 0 3
a
f  o z
i o r
o
O  d n
o  - -
o
o)
5  3  5 . 5  5 . 7  s . 9
1O,O00/T(K)
Fig. l. Viscosity-temperature relationships of liquids on the
(a) Na,SiO.-TiO, and (b) CaSiO.-TiO, joins.
linear function of composition in the CaSiOr-TiO, sys-
tem, whereas there is a slight negative deviation from
additivity in the NarSiOr-TiO, system. The Na,SiOr-TiO,
data of Figure la extrapolate to values in good agreement
TABLE 2A. Viscosity determinations (NTS and CTS)
- o 4
- 0 5
10 20 30 40 50 60
Mol % TiO,
Fig.  2.  Viscosi ty-cornposi t ion re lat ionships on the (a)
NarSiOr-TiO, and (b) CaSiO, joins.
with those obtained by Bockris et al. (1955) on NarSiO,
liquid, and the data from the CaSiO3-TiO, join (Fig. lb)
agree well with the viscosity data of Bockris and Lowe
(1954) and Urbain et al. (1982).
- o 3
- o 4
- 0 5
Viscosity (dPaS)
Temp.
("c) CTSO CTS1 CTS2 CTS3 CTS4 CTSs CTS6 CTST CTSS
1594
1 569
1544
1520
1 495
1471
1446
1421
1 397
2.O4 1.67
1.82
2.O7
2.38
2.76
1 .21
1.34
1 .51
1 .72
1 .97
2.27
0.880
0.983
1 . 1 0
1.25
1.42
1.63
1.89
2.21
2.60
0.638
0.721
0.781
0.878
0.987
1 . 1 2
1.28
1.49
1.74
o.497
0.535
0.583
0.u7
0.724
0.814
o.924
1.06
1.23
o.344
0.373
0.404
0.443
0.491
0.550
0.620
o.715
0.809
o.223o.275
0.333
NTSl NTS2
1 151
1126
1't02
1077
1052
1 028
1003
978
4.94
5.48
6.62
8.01
9.78
12.9
14.5
3.47
4.00
4.70
5.56
6.61
8 .10
9.45
1 1 . 6
2.2'l
2.55
2.94
3.41
4.00
4.66
1 .66
2 .15
2.49
2.93
3.48
1 .27
1.45
1.68
1 .96
2.33
2-80
/Votej Viscosity data are accurate to +5% at 2o. Note that these values are in dPaS, not in log,o units.
DINGWELL: SHEAR VISCOSITY OF SILICATE LIQUIDS 273
2 . 6
2 . 2
{/nrisiou
TABLE 3. Arrhenius parameters
Sample 5 x 1 @
Number
of data
: 1 8
(L
9 t +
R  r n
o
ot o 6
-  o . 2
CTSl
CTS2
CTS3
cTs4
CTS5
CTS6
NTSl
NTS2
NTS3
NTS4
NTSS
CsTS5
RTS5
KTS5
BTSS
STS5
LTS5
-3.730(0.009)
-3.80s(0.005)
-4.052(0.006)
-3.877(0.008)
3.678(0.010)
-3.644(0.010)
-3.613(0.01 9)
-3.307(0.005)
-3.185(0 005)
-3.393(0.004)
-3.762(0.01 1)
-3.983(0.019)
-4.141(0.030)
-3.140(0.004)
-4.031(0.028)
-3 684(0.01s)
-2.841(0.011)
7.367(0.037)
7.249(0.016)
7.444(0.010)
6.859(0.013)
6.270(0.016)
5.914(0.01 5)
6.1 07(0.026)
s 472(0.005)
5.022(0.004)
5.1 1 9(0.00s)
5.485(0.010)
6.343(0.663)
6.701 (0.1 24)
5.1 66(0.004)
6.948(0.237)
6.343(0.444)
4.233(0.1 30)
5
6
9
I
I
I
1 0
e
o
1 1
9
1 3
4
1 1
- o 2
- o 6
7 8
10,000/r(K)
Fig. 3. Viscosity-temperature relationships for melts of the
stoichiometry Xi;TiSiO5.
Figure 3 illustrates the viscosity-temperature relation-
ships of the liquids of sphene stoichiometry. The alkaline
earth liquids cluster tightly with a slight decrease from
Ba > Sr > Ca. Similar results have been observed for the
alkaline earth galliosilicates (Dingwell, 1990; Balewick and
Shelby, 1990), aluminosilicates (Urbain et al., 1982), and
ferrosil icates (Dingwell, 1989b). The relative field
TABLE 28. Viscosity determinations (XTSs)
Note.' Numbers in parentheses are standard errors on the linear regres-
sions. Not to be used for extrapolation of temperature-viscosity relation-
shios.
strengths of the alkaline earth cations have a structural
influence on these liquids whose effect for viscosity tran-
scends the identity of the third cation (Ti, Al, Ga, or Fe).
The shear viscosity ofthe alkali titanosilicates ofsphene
stoichiometry is more sensitive to cation identity. The
1 0
Viscosity (dPaS)
Temp. ("C) RTS5 KTSS LTS5 BTS5 CTS5
1 625
1 594
1 569
1544
1520
1 495
1471
1446
1421
1 397
1 378
1 348
1323
1298
1273
1249
1  1 5 1
1  126
1102
1077
1 052
1 028
1 003
978
9s4
925
900
875
850
825
800
775
750
16.2
26.3
46.8
89.1
1 5 1
13 .5
17 .O
21.4
26.9
36.3
47.9
67.6
91.2
135
170
282
3.08
3.58
4 .16
4.85
s.70
6.78
8 .11
o E o
12.O
1 .27
1.45
1 .68
1 .96
2.33
2.80
0.250
0.268
0.291
0.304
0.327
0.353
0.381
o 407
o.447
0.490
0.559
0.670
0.738
0.817
0.901
0.993
1 . 1 2
1.30
1.50
1.75
2.06
2.47
3.01
3.69
0.695
o.497
0.535
0.583
o.647
o.724
0.814
0.924
1.06
1.23
o.467
0.563
/Vofe.-Viscosity data are accurate to +57" at 2o. Note that these values are in dPaS, not in loglo units.
274
viscosity decreases 0.6 log,o units with alkali substitution
from Cs to Na. Data for the Li composition are insuffi-
cient to distinguish the trend further. The general behav-
ior of the alkali titanosilicates matches again that of the
equivalent gallio-, alumino-, and ferrosilicate liquids.
One apparent contrast to the trends observed for gal-
lio-, ferro-, and aluminosilicate liquids is the observation
that the alkali titanium silicates have lower viscosities
than the alkaline earth titanium silicate liquids. In a com-
panion study, the densities of all of the investigated liq-
uids have been determined (Dingwell, in preparation).
The partial molar volume of TiO, has been computed for
each of the liquids of sphene stoichiometry. The partial
molar volume of TiO, is alkali-cation specific. In general,
much larger values are observed for the alkali vs. the
alkaline earth titanium silicates and pure TiO, liquid
(Dingwell, 1991), suggesting that Ti has a lower coordi-
nation number in the alkali titanium silicates. The ap-
parent shift in coordination number of Ti in the alkali
titanium silicate liquids may be responsible for the lower
viscosity observed for the alkali silicate vs. the alkaline
earth silicate liquids.
AcrNowr,rocMENTS
I thank DedefKrau8e and Kurt Klasinski for technical assisrance, Charles
Ross II for X-ray diffraction work, and Anna Dietel for ICP-AES analyses
RrrpnpNcns crrED
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and barium galliosilicate glasses Journal of the American Ceramic So-
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DINGWELL: SHEAR VISCOSITY OF SILICATE LIQUIDS
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-(1991) The density of liquid TiO,. Journal of the American Ce-
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-(1990) Relaxation in silicate melts. European Journal of Miner-
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chemical signatures of island arc volcanics and continental potassic
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I E
Gunter, W.D., Hoinkes, G., Ogden, P., and Pajari, P.E. (1990) Origin of
leucite-rich and sanidine-rich flow layers in the lrucite Hills Volcanic
Field, Wyoming. Journal of Geophysical Research, 95, I 59 I l- I 5928.
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Mnxuscprm rucErwD Aucusr 12, l99l
MeNuscnryr AccEprED Noveusrn 5. l99l


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Shear viscosity of alkali and alkaline earth titanium silicate liquids

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