Results of X-ray diffraction (XRD), differential scanning calorymetry (DSC), electron probe microanalysis (EPMA) and optical absorption of InF3-based glasses are reported. Different concentrations of rare earth ions have been added to a base glass. XRD results show that no crystalline phases are formed. Characteristic temperatures were determined by DSC and values of glass stability parameters were calculated. Also, the effect of rare earth ions on the thermal stability of InF3-based glasses has been investigated. From the optical absorption measurements and Judd- Ofelt method the intensity parameters have been calculated. In consequence the trends of the intensity parameters are discussed as a function of the number of 4/electrons

Goryczka, Tomasz

Pisarska, Joanna

Pisarski, Wojciech A.

Ryba-Romanowski, W.

Zelechower, M.

Ślęzok, M.

Optica Applicata

English

Repozytorium Uniwersytetu Śląskiego RE-BUŚ

             Title: Physical properties of InF3-based glasses  Author: Joanna Pisarska, M. Ślęzok, M. Zelechower, Wojciech Pisarski, Tomasz Goryczka, W. Ryba-Romanowski  Citation style: Pisarska Joanna, Ślęzok M., Zelechower M., Pisarski Wojciech, Goryczka Tomasz, Ryba-Romanowski W. (2003). Physical properties of InF3-based glasses. "Optica Applicata" (2003, iss. 1, s. 133-139). Optica Applicata, Vol. XXXIII, No. I, 2003Physical properties of InF3-based glassesJoanna Pisarska1, M aria Ślęzok1, M ichalŻelechower1, W ojciech A. Pisarski2, Tomasz Goryczka2, W itold Ryba-R omanowski3'Silesian University of Technology, Department of Materials Science, ul. Zygmunta Krasińskiego 8, 40-019 Katowice, Poland.2University of Silesia, Institute of Physics and Chemistry of Metals, ul. Bankowa 12, 40-007 Katowice, Poland.institute of Low Temperature and Structure Research, Polish Academy of Sciences, ul. Okólna 2, 50-395 Wroclaw, Poland.Results of X-ray diffraction (XRD), differential scanning calorymetry (DSC), electron probe microanalysis (EPMA) and optical absorption of InF3-based glasses are reported. Different concentrations of rare earth ions have been added to a base glass. XRD results show that no crystalline phases are formed. Characteristic temperatures were determined by DSC and values of glass stability parameters were calculated. Also, the effect of rare earth ions on the thermal stability of InF3-based glasses has been investigated. From the optical absorption measurements and Judd- Ofelt method the intensity parameters have been calculated. In consequence the trends of the intensity parameters are discussed as a function of the number of 4/electrons.Keywords: fluoroindate glasses, rare earth fluoride, physical properties.1. IntroductionHeavy metal fluoride glasses (HMFG) have been studied extensively in recent years [l]-[5 ]. In particular, glasses based on indium fluoride have drawn attention because of their attractive optical properties such as lower phonon energy, wide IR transmission range, as well as higher thermal stability in the other ones. Recently, the optical properties of InF3-Z nF 2 -B aF2-SrF 2 -G aF 3 -N aF (IZBSGN) systems singly doped with Tm3+ and doubly doped with Tm3+ and Tb3+ ions have been investigated [6]. In this paper, we provide some information about thermal and optical properties of InF3-based glasses doped with different concentrations of rare earth fluorides. The detailed knowledge about how do these properties change as a function of the modifiers addition and the rare earth doping to the base glass is crucial in the evaluation of a glass matrix as a laser media host or optical waveguide.134 J. Pisarska et al.2. ExperimentalX-ray diffraction (XRD) patterns of glass samples were obtained using INEL diffractometer with Cu Ka radiation in 20 range from 0° to 120°. Homogeneity measurements (EPMA) were performed using scanning electron microscope (JSM 35) coupled with an energy dispersion X-ray spectrometer (LINK 860). Characteristic temperatures were determined from a differential scanning calorymetry (DSC) analysis (Perkin-Elmer). Optical absorption spectra were recorded with a Varian 2300 UV-VIS-NIR spectrophotometer.3. Results and discussion3.1. Synthesis and characterization of lnF3-based systemsSeveral glass matrices of nominal compositions (in mol%): 40InF3-20ZnF2-20BaF2-  20SrF2 (IZBS) and 36InF3-20ZnF2-16BaF2-20SrF2-6G aF3-2N aF (IZBSGN) were prepared using anhydrous fluorides of 99.99% purity (Aldrich) as starting materials. In doped samples the InF3 was substituted partially in order to obtain systems singly doped with 2% and 8% of Eu3+, 0.5% and 6% of Ho3+, 0.5% and 5% of Tm3+. To prepare samples, several batches were mixed homogeneously and heated in dry argon atmosphere. Glasses were melted at 850 °C in a platinum crucible, then poured into preheated copper moulds and annealed below the glass transition temperature Tg. After this process, samples were slowly cooled to the room temperature. Some of the physical properties including: characteristic temperatures, stability parameter and refractive index of undoped IZBS and IZBSGN glasses, in comparison to other glasses based on InF3, are presented in Tab. 1. Different Tg and AT values are observed for our IZBS glass and glass with the same composition but obtained by other co-workers. This discrepancy probably can be associated with different conditions in which the samples were prepared. The stability parameter AT increases when glass-modifiers such as GaF3 and NaF substitute for InF3 and BaF2. In the presence of these modifiers the stability parameter AT is higher than for IZBS and other glasses well described in literature.3.2. XRD and EPMA studiesThe preliminary X-ray diffraction analysis of InF3-based glasses (IZBSGN) doped with rare earth ions was carried out. Figure 1 shows the X-ray diffraction patterns obtained for glasses doped with Eu3+, Ho3+, Tm3+ ions. The XRD patterns of our glasses display two broad peaks corresponding to the remaining amorphous phases, independently of rare earth doping concentration. The same behavior is observed in the case of an undoped sample. In contrast to other InF3-based glasses these findings are in a good agreement with the results obtained for IZBSGa and IZBSMg after heat treatment, where no crystalline phase was detected [2]. In order to obtain additional information on the crystallizing phases, X-ray diffraction measurements should be performed after the heat treatment. EPMA measurements indicate a good chemicalT a b l e  1. Physical characteristics of glasses in the InF3-based system. Characteristic temperatures Tg and Tx, stability parameter AT and refractive index nD from this study compared with other heavy metal fluoride glasses based on indium fluoride.Sample Composition [mol%] 7g [°C] Tx [°C] AT [°C] Ref.IZBS 40InF3-20ZnF2-20BaF2-20SrF2 1.501 301 388 87 [1]IZBSNa 36InF3-30ZnF2-15BaF2-20SrF2-4NaF — 307 370 63 [2]IZSBNa 30InF3-30ZnF2- 15 B aF2-20S rF2-5  NaF 1.487 290 380 90 [3]IZBGdCa 40InF3-20ZnF2-25BaF2-10GdF3-5CaF2 — 309 403.6 94.6 [4]IZBGdCaY 46InF3-20ZnF2-30BaF2-2GdF3-5CaF2-2YF3 — 303 278.9 75.9 [4]IZBSCa 36InF3-30ZnF2-I5BaF2-20SrF2-4CaF2 — 302 375 73 [2]IZSBC 40InF3-20ZnF2-15BaF2-20SrF2-5CaF2 1.495 295 385 90 [3]IZBSCd 36InF3-20ZnF2-20BaF2-20SrF2-4CdF2 — 301 390 89 [2]IZSBCd 40InF3-20ZnF2- 15BaF2-20SrF2-5CdF2 1.498 291 383 92 [3]IZSBPb 40InF3-20ZnF2-25 B aF2-5SrF2- 10PbF2 1.530 277 366 89 [3]IZBSMg 36InF3-20ZnF2-20BaF2-20SrF2-4MgF2 — 311 405 94 [2]IZBSGa 36InF3-20ZnF2-20BaF2-20SrF2-4GaF3 — 309 414 105 [2]IZBSY 36InF3-20ZnF2-20BaF2-20SrF2-4YF3 — 309 395 86 [2]IZBSZr 36InF3-20ZnF2-20BaF2-20SrF2-4ZrF4 — 306 391 85 [2]IZBGd 40InF3-20ZnF2-30BaF2- 10GdF3 — 309 392.2 83.2 [4]IZBGdAl 40InF3-20ZnF2-25BaF2-10GdF3-5AlF3 — 310.7 400 89.3 [4]IZBGdSr 40InF3-20ZnF2-20B aF2- 10GdF3- 10SrF2 — 300 405 105 [4]IZBSGd 36InF3-20ZnF2-20BaF2-20SrF2-4GdF3 — 317 360 43 [2]IZBSGdNa 40InF3-20ZnF2-15BaF2-20SrF2-3GdF3-2NaF 1.498 291 383 92 [5]IZSBGdNa 40InF3-20ZnF2- 16BaF2-20SrF2-2GdF3-2NaF 1.493 289 390 101 [3]IZSBGdL 40InF3-20ZnF2-17BaF2-20SrF2-2GdF3-lL aF3 1.508 294 390 96 [3]IZBS 40InF3-20ZnF2-20BaF2-20SrF2 — 292 392 100IZBSGN 36InF3-20ZnF2- 16BaF2-20SrF2-6GaF3-2NaF 1.48 294 404 110U>Physical properties of InF3-based glasses136 J. Pisarska et al.Fig. 1. X-ray diffraction patterns of InF3-based glasses doped with Eu3+, Ho3+ and Tm3+ ions.T a b l e  2. Results of elemental homogeneity measurements.IZBSGNEu 8 mol% Eu In Ba Eu Zn Ga SrAverage intensity [counts] 8530 3696 672 3898 803 846Standard deviation [counts] 266 93 148 238 51 50Relative mean error [%] 1.4 1.1 9.9 2.7 2.8 2.7IZBSGNEu 2 mol% Eu EuAverage intensity [counts] 8375 3678 2154Standard deviation [counts] 526.4 371.8 131.7Relative mean error [%] 2.0 3.2 1.9IZBSGNTm 0.5 mol% Tm In Ba Tm Zn Ga SrAverage intensity [counts] 11315 4440 152 4045 195 714Standard deviation [counts] 283 46 32 72 52 34Relative mean error [%] 1.1 0.5 9.4 0.8 12.0 2.1IZBSGNTm 5 mol% Tm TmAverage intensity [counts] 11420 2179 2555Standard deviation [counts] 265.5 147.9 160.2Relative mean error [%] 0.7 2.1 2.0IZBSGNHo 0.5 mol% Ho In Ba Ho Zn Ga SrAverage intensity [counts] 9989 10040 1201 3910 775 2221Standard deviation [counts] 271 278.2 80.9 197 50 81.3Relative mean error [%] 1.2 0.9 2.1 2.5 2.7 1.2IZBSGNHo 6 mol% Ho HoAverage intensity [counts] 10925 5737 2360Standard deviation [counts] 844.6 846.5 257.8Relative mean error [%] 2.4 4.7 3.5Physical properties of InFybased glasses 137homogeneity of our glasses. Results of homogeneity measurements are presented in Tab. 2. In most cases, for elements with a high concentration the relative mean error does not exceed 3%, however, for elements with a low concentration (Ga, rare earth) it reaches the value close to 10%.3.3. DSC studyFrom DSC curves characteristic temperatures such as glass transition temperature Tg, crystallization onset Tx and maximum of the crystallization peak Tp were obtained, from which stability parameter AT was calculated for undoped IZBS and IZBSGN glasses, as well as for both glasses doped with 2 mol% of Eu3+. As mentioned in Sec. 3.1, the stability parameter AT increases from 100 °C for IZBS up to 110 °C for IZBSGN with the addition of GaF3 and NaF (Tab. 1). The same behaviour is observed for samples doped with Eu3+ ions. Then, the stability parameter AT increases from 108 °C for IZBSEu up to 112 °C for IZBSGNEu. The thermal properties of IZBSGN glasses containing different concentrations of rare earth ions have been examineda b cFig. 2. DSC curves of InF3-based glasses doped with Eu3+ (a), Ho3+ (b) and Tm3+ (c) ions.T a b l e  3. Thermal properties of InF3-based glasses doped with rare earth ions.Ln-doped sample Tg [°C] Tx [°C] Tp [°C] AT [°C] H S2 mol% EuF3 294 406 431 112 0.38 9.528 mol% EuF3 307 389 398 82 0.27 2.400.5 mol% HoF3 294 410 420 116 0.39 3.956 mol% HoF3 306 386 399 80 0.26 3.400.5 mol% TmF3 294 409 430 115 0.39 8.215 mol% TmF3 300 388 394 88 0.29 1.76138 J. P isarska et al.(Fig. 2). The results are presented in Tab. 3. The thermal stability of the base glass has been found to increase upon the incorporation of no more than 2 mol% of rare earth ions. These results show that the addition of rare earth fluoride to the base glass lowers the crystallization rate and causes an increase in the thermal stability of the base glass. Adding above 5 mol% of rare earth fluoride causes an extremely strong decrease in the thermal stability parameter. It has been pointed out that our glass system, in which GaF3 and NaF were used as modifiers in InF3-based glass doped with rare earth ions in the limit of low concentration, is more stable than the other one.3.4. Optical studyRelaxation of excited states in the InF3-based glasses containing different concentrations of Eu3+, Ho3+ and Tm3+ ions has been examined in our previous work [7]. Emission properties of these glasses doped with rare earth ions strongly depend on activator concentration. For higher activator concentration, strong luminescence quenching related to the contribution of activator-activator interaction by cross -relaxation processes is observed. Emission spectra and lifetimes of excited states give evidence that cross-relaxation processes are quite efficient in the InF3-based glasses. From the optical absorption measurements and Judd-Ofelt method the intensity parameters have been obtained for rare earth ions in the InF3-based glass. The trends of the Judd-O felt intensity parameters Q are examined as a function of the number of 4 / electrons. Figure 3 shows the variation of these parameters according to the rare earth series for InF3-based glass. The parameter Q2 does not exceed 2x10"20 cm2 for all rare earth ions in our glass system. The small values of parameter Q2 indicate that these glasses have a good chemical homogeneity [8] and are less covalent in character than the ZrF4-based one [9]. The observed monotonous decrease in the intensity parameters QA and jQ6 for rare earth ions in our glasses shows the dominant static mechanism of the Judd-O felt theory. In contrast to the crystalline materials, where Q4Fig. 3. Variation of the Judd-Ofelt intensity parameters Q t (t = 2, 4 ,6) along the lanthanide series for the InF3-based glass.Physical properties of InFybased glasses 139and Q6 values lie on a U-shaped curve [10] due to electron-phonon coupling, which is strong at the beginning and at the end of rare earth series [11], vibronic contributions to the transition intensities do not play an important role in the InF3-based glass.4. ConclusionsThe InF3-based glasses have been obtained. In particular, glasses based on IZBSGN systems are more stable. Physical properties of these glasses using XRD, EPMA, DSC methods as well as optical absorption have been investigated. X-ray diffraction patterns do not reveal neither strong diffraction line due to the precipitation of InF3 nor other crystalline phases. Stability parameters were calculated basing on DSC measurements. The effect of (GaF3, NaF)/(InF3, BaF2) substitution and rare earth doping on thermal properties of InF3-based glasses has been found. Stability parameter A T  increases with the addition of glass modifiers such as GaF3, NaF. In the limit of low activator concentration, thermal stability increases and the drastic decrease starts at higher concentration. The observed monotonous decrease in the parameters Q4 and Q6 from the Pr3+ ion to the Tm3+ ion shows that the vibronic contributions to the transition intensities in the InF3-based glasses are not important. Additionally, small values of parameter Q2 suggest the high degree of homogeneity of these glasses, what was confirmed by EPMA results.Acknowledgments -  This work was supported by the Polish State Committee for Scientific Research (KBN) under grant No. 7 T08D 020 21.References[1] Poulain M., Poulain M„ J. Non-Cryst. Solids 213-214 (1997), 40.[2] Dakui Dong, Zhonglin Bo, Jiqian Zhu, Fuding Ma, J. Non-Cryst. Solids 204 (1996), 260.[3] Messaddeq Y., Delben A., Boscolo M , Aegerter M.A., Soufiane A., Poulain M., J. Non-Cryst. Solids 161 (1993), 210.[4] M essaddeq Y., Inoue S„ Ribeiro C.T.M., N unes L.A.O., J. Non-Cryst. Solids 213-214 (1997), 179.[5] Qiu J., Maeda K., Terai R., Wakabayashi H., J. Non-Cryst. Solids 213-214 (1997), 363.[6] R yba-Romanowski W., Goiab S., D ominiak-D zik G., Żelechower M., Pisarska J., J. Alloys Compd. 325 (2001), 215.[7] Gabryś-Pisarska J.,ŻelechowerM., Pisarski W.A., Gołąb S., BałukaM., Ryba-Romanowski W., Opt. Appl. 30 (2000), 517.[8] Reisfeld R., Jorgensen C.K., Excited state phenomena in vitreous materials, [In] Handbook on the Physics and Chemistry o f Rare Earth, Elsevier Science Publishers, 1987, Chap. 58.[9] Tanabe S., J. Non-Cryst. Solids 259 (1999), 1.[10] Peacock R.D., Str. Bonding (Berlin) 22 (1975), 83.[11] M eijerink A., B lasse G., Sytsma J., de M ello D onega C., Ellens A., Acta Phys. Pol. A 90 (1996), 109.Received September 26, 2002

Physical properties of InF3-based glasses

https://rebus.us.edu.pl/bitstream/20.500.12128/14896/1/Pisarska_Physical_properties_of_InF3_based_glasses.pdf

Physical properties of InF3-based glasses

Abstract

Similar works

Full text

Available Versions

Repozytorium Uniwersytetu Śląskiego RE-BUŚ