Pathak, P D

Shah, N P

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Surface energy o f molten metalsr  T) P athak  and  M P Sila.itPhysioa Depnrtmcnf, ihriverstti/ Hchaal of Sctcnoeji, AIwiedabad-^^0009 {Rfcmved Hi fJecember 1975)In thin uoto aji attomx>t inad(^  to .show lhat a lolatiou oxista betweon aurfacc c»norgy, molting tomjioi'atnro and wavolongfch m tho cjaao of moJton motals.Tlu^  rolatiou hotwooji t,om]iroaail)ility K, anrfao(» onorgy tr and Fermi wave- longWi Kf civ(m by (Brown & March 1973),iCrr-- Ott/IGO iO? ... (1)Thus the i>r(HluGt Kcr should bo of the, oixler of the do Broglie Avavoleiigth for an ot^itron at tJu' FtM ini smlacc^Tu tlio case of alkali halidea Pathak & Vasavada (1970a) havo s3\o\m tliatIndian J. Phya. 50 , 7 9 2 -7 9 3  (1976)VE f- OK (2 )Mahore V ii^  the volum e i^or m ole, E f  is the em^rgy o f  vacancy form ation  and 0  iH a (ionstant TJ»,o generality o f  tlio argumtmt for d o m in g  th.is relation  h1t,ows thal it slioukl ho equally valid foi“ m otalsIn the case of motals Pathak & VaiSavada (1970b) hare sh<n\n that thi' relation between Ef and the melting temperature I'm. isEf{oV) -  7-03X lO-^T^w ... (3)Combining oqs (2) and (3) we getr « „  ■ WAvhere O ' is a constantTt was inUyi’osting to find tJiat this nfiation holds also for molten metals. This can bo somi from table 1Table 1 Relation betwi'on compressibility K  and molting tciinpei atuj’o Tm foi* molten motalsMoial VITm ( X 1(P) (end molo-^ K-^]2C ( X 10 2^)( (cm^  dyne” )^VjKTm ( X 10-'^ )Na 63.9 21 304K 136.3 40 338Rh 179 1 49 365Ch 231.0 67 344(Ju 6 26 1.46 362Ag 8 31 1.86 446Zn 13.3 2.4 663C(l 21 9 3 2 683Pb 30.6 3.6 873Bi 39.2 4.3 911792P. D. Pathak and N. P, Shall 793In table 1, the valne.s of tho comproKHibilitioH are taken from Egolfitaff & Wklom (1970). It can bi) Moon from the table tliat althougli tho compu^ ':^ Hibiliti<^ ;^ ’^^ ary by a factor of about 50, tho valnofj in tho last oolnmn vajy by a factor ol about 3In view of the above ai-gumontfl wo can c nmbino oq.s, (1) ivncl (4) for molto.n motalH tuid goi<V<tK f , ,Tm ~Tlio valuen of tlie loft hand side ai o shown m table 2(5)Table 2. Relation boiwo(^n siirfaijo energy cr, mcdting tomi)oratinv Tin and Fermi waveloiigtli Kp for molboi metalsMetal tr*(dyno-cm) (crn~^ )Na 191 0.90 10.98K 101 0.73 9.98Rb 77 0.68 9.38Cu 1086 1.36 7.71Ag 785 1.19 7.77Au 754 1.20 6.01Zn 824 1.57 17.10Cd 664 1.40 17.26A1 916 1.75 17.13In 340 1.50 18.71Tl 400 1.46 17.42Sn 626 1.03 27.68Pb 444 1.67 21.30Bi 376 1.61 23.71*Tho values of cr m the above liable aro taken from Flynn (1964).Ft is seen from the above table that although V(tKf IT„i remains fairly constant for tho difforont groups of nn -^als, no simple correlation with Z e.tui be found 1!lxis note is communicated with a hope that it will stimulate further thc^oretioal considerationsFinaiuual assistance to one of ns (NFS) by the Council of Scuontifie and Industrial Rosoareh is gratefully’’ aoknowledgerlREFEB£N0E.SBrown R. C. & March N. H. 1973 J. Phys. G : Solid St Phys 6. L363. Egelstoff P. A & Widom B. 1970 J. Chem. Phya. 53. 2607.Plynn C. P. 1064 J. Appl. Phys. 35. 1641.Pathak P. D. & Vanavada N. O. 1970a J. Phya. D ■ Appl. Phys. 3, 1707 ------------ - ----------------------------- 1970b J. Phya. 0  : Solid St. Phs/a 8, 44,10

Surface Energy of Molten Metals

http://arxiv.iacs.res.in:8080/jspui/bitstream/10821/4564/1/Surface%20Energy%20of%20Molten%20Metals_P%20D%20Pathak.pdf

Surface Energy of Molten Metals

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