Structure-Property Correlations in Borate, Silicate and Tellurite Glasses

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1 Indo-French Workshop on Glasses and Glass-ceramics University of Science and Technology, Lille, France 6-8, June, 2012 Structure-Property Correlations in Borate, Silicate and Tellurite Glasses Atul Khanna Department of Physics Guru Nanak Dev University Amritsar , Punjab, India

2 CITY OF AMRITSAR, PUNJAB, INDIA GOLDEN TEMPLE

3 GURU NANAK DEV UNIVERSITY, AMRITSAR Established in State Government Funded and Affiliating University. 12,000 Students on Campus, and about 300 affiliating Colleges in the state of Punjab. 350 Faculty Teachers on Campus

4 Overview of Research Activities on Glasses at GNDU, Amritsar: Synthesis and Characterization of Binary Borate, Borosilicate aluminoborosilicate, lead silicate, binary tellurite, borotellurite and aluminoborotellurite glasses and glass-ceramics Characterization Techniques: Density Measurements UV-visible spectroscopy DSC Raman spectroscopy High-Q Neutron Diffraction B 11 and Al 27 MAS NMR Low Temperature C p measurements in glasses and glass-ceramics Insitu High Pressure synchrotron infrared spectroscopy

5 Intriguing metastability in lead and bismuth borate melts Rapid changes in liquid properties with temperature Fragility Fragile liquids evolve rapidly with temperature Lead and bismuth borate melts are highly fragile liquids Evolve with time too!!!

6 Structure of Bismuth Borate glasses by 11 B MAS NMR at 16.2 Tesla 11 B MAS NMR spectra Fraction of tetrahedral Borons in glasses, N 4 Bajaj et al. J-Non Cryst. Solids 355(2009)45-53

7 DSC thermograms of bismuth borate glasses Exothermic and Endothermic peaks disappear during second heating cycle of DSC. Bajaj et al. J-Non Cryst. Solids 355(2009)45-53

8 Crystallization (devitrification) of bismuth borate glasses Bi 2 O 3-4B 2 O 3 Bi 2 B 8 O 15 Bismuth octaborate phase 3(Bi 2 O 3-4B 2 O 3 ) 2Bi 3 B 5 O B 2 O 3 (Bi 2 O 3-3B 2 O 3 ) 2BiB 3 O 6 Bismuth triborate phase 4(Bi 2 O 3-3B 2 O 3 ) Bi 2 B 8 O Bi 3 B 5 O 12 +3B 2 O 3 2Bi 2 O 3-3B 2 O 3 Bi 3 B 5 O 12 + BiBO 3 Bismuth orthoborate phase

9 BiBO 3 is metastable and decomposes on heating 7BiBO 3 Bi 3 B 5 O 12 + Bi 4 B 2 O 9 7(3Bi 2 O 3-2B 2 O 3 ) 9Bi 4 B 2 O 9 + 2Bi 3 B 5 O 12 Bajaj et al. J. Phys. Condens. Matter 21(2009)035112

10 Bi 3 B 5 O 12, Bi 2 B 8 O 15, BiBO 3 and Bi 4 B 2 O 9 crystalline phases produced by devitrification of the Bi 2 O 3 -B 2 O 3 glasses and characterized by FTIR spectroscopy, XRD, DSC and NMR Glasses upto 33 mol % of Bi 2 O 3 form Bi 2 B 8 O 15 phase along with predominant Bi 3 B 5 O 12 phase. Glasses with Bi 2 O 3 content of 40 to 50 mol % form metastable BiBO 3 phase. Glasses with higher Bi 2 O 3 content form Bi 4 B 2 O 9 phase

11 Rare earth ion doping in bismuth borate glasses stabilizes the formation of BiBO 3 on devitrification Bajaj et al. J. Am. Ceram. Soc. (2009)

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13 Radial Distribution Function in Bi 2 O 3 -B 2 O 3 Glasses

14 FSDP grows Intermediate Range Order (IRO) increases with melt temperature

15 DTA patterns of Bi 2 O 3 -B 2 O 3 glass samples prepared with increasing melt annealing time. 0 DTA signal Sample No. Tg ( o C) T( o C)

16 Transparent Nano-Glass Ceramics of Bismuth Borates Prepared by Tailoring Melt History Glass Crystalline Nano-Glass Ceramic Nano-Glass Ceramic Glass

17 Lead borate glasses ( PbO = mol %) DSC patterns 11 B MAS NMR 3PbO-7B 2 O 3 3PbB 4 O 7 + B 2 O 3

18 Lead aluminoborate glasses PbO=50 mol %, Al 2 O 3 =2-8 mol % Glass density falls on adding Al 2 O 3 N 4 decreases from 43 to 29 % Crystallization tendency suppressed Saini et al. J-Non Cryst. Solids 355(2009)2323

19 Lead borosilicate glasses (PbO= 50 mol % & SiO 2 =5-30 mol %) & Lead aluminoborosilicate glasses (PbO=50 mol %, SiO 2 = 5 mol % & Al 2 O 3 =2-8 mol % ) Lead aluminoborosilicates Lead borosilicates Saini et al. J-Non Cryst. Solids 355(2009)2323

20 27 Al MAS NMR of lead borate & borosilicate glasses doped with Al 2 O 3 Al 2 O 3 =8 mol % Al in hexa, penta and tetra co-ordinations AlO 4 = 70% AlO 5 +AlO 6 =30% Al 2 O 3 =2 mol % Saini et al. J. Non-Cryst. Solids 355(2009)2323

21 Density of 30PbO-70B 2 O 3 glasses increases with melt annealing time and temperature

22 Two Glass Transitions Observed in Glass with Maximum Melt Heat Treatment T g decreases by 3 o C 3PbO-7B 2 O 3 3PbB 4 O 7 + B 2 O 3

23 Needle like crystals form in PbO-B 2 O 3 glass quenched from melt at 750 o C

24 Crystals disappear in PbO-B 2 O 3 glass if melt annealed for time longer than about 2 hours

25 Density of 25Bi 2 O 3-75B 2 O 3 glass as a function of melt history Bi weight concentration same in all samples within 1 % by EDTA titration

26 Single crystals of α-bib 3 O 6 have density lower than density of glass of equal composition ρ = g cm -3 Two other polymorphs of BiB 3 O 6 found in 2005: β-bib 3 O 6 (ρ =5.411 g cm -3 ) (N 4 = 66.6 %) γ-bib 3 O 6 (ρ=6.11 g cm -3 ) (N 4 = 100 %) α Bi 3 BO 6 β-bi 3 BO 6 γ-bi 3 BO 6 α-bib 3 O 6 N 4 = 33.3 % Teng et al. J. Cryst. Growth (2001) Li et al. Inorganic Chemistry (2005)

27 SAXS studies on lead and bismuth borate glasses Curious phase separation (heterogeneity) in lead & bismuth borate borate glasses. EPMA mapping by WDX revealed that B, Pb and O content was same everywhere. SEM Micrograph of Lead Borate Glass Heterogeneity is structural rather than compositional Unusual L-L phase separation POLYAMORPHISM

28 Ultra Small Angle X-Ray Scattering(USAXS) Studies on Lead and Bismuth Borate Glasses Experiments Done at APS, ANL Strong USAXS Signal Heterogeneities of ~10 3 nm

29 Lead and Bismuth Borate Melts Highly Fragile Glass Formers These liquids evolve rapidly with temperature What is the Effect of Pressure on Structure of Glasses & Melts? Phase Transitions in Amorphous Materials?

30 Co-ordination Number of Boron with Oxygen varies from 3 to 4 in borate glasses and crystals. Fraction of Tetrahedral Borons: N 4 = BO 4 /(BO 4 +BO 3 ) Boron Co-ordination Number or N 4 is important structural parameter of borate and borosilicate glasses.

31 Studied the Effect of Pressure (upto 25 GPa) on Boron Co-ordination in Lead and Bismuth Borate Glasses: 30 PbO-70B 2 O 3 57PbO-43B 2 O 3 40Bi 2 O 3-60B 2 O 3 50Bi 2 O 3-50B 2 O 3 Experimental Technique: Insitu Mid-Infrared Absorption Spectroscopy at U2A Beamline of NSLS, Brookhaven National Laboratory.

32 B 11 MAS NMR patterns IR Spectra of Borates N 4 = (Ratio of area under BO 4 absorption band to the total area under the two bands) x (Normalization constant for area ratio from ambient pressure N 4 value measured by B 11 MAS NMR)

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37 Mechanism of Boron Co-ordination Increase with Pressure: Consumes Non-Bridging Oxygens (NBOs) I. BO 3 + NBO BO 4 in the glass network and increases rigidity. II. BO 3 + Bridging Oxygens BO 4 (with Oxygens Triclusters) (Oxygen Triclusters are triply co-ordinated oxygens) n BO = 3+N 4 C O n OB =C B n BO f NBO =2-n OB (Assuming Bi and Pb atoms do not participate in glass network formation) 30PbO-70B 2 O 3 f NBO = 0.05 (At Ambient Pressure) 57PbO-43B 2 O 3 f NBO = Bi 2 O 3-60B 2 O 3 f NBO = Bi 2 O 3-50B 2 O 3 f NBO = 0.84 Greater increase in N 4 in bismuth borates due to higher f NBO values.

38 PbO-SiO 2 Glasses Density DSC TEC & Microhardness Dilatometery Khanna & Kothiyal

39 Preparation & Characterization of PbO-TeO 2 and ZnO-TeO 2 glasses Kaur et al. J. Non-Cryst. Solids 356(2010)864

40 Effect of melt quenching rate on the optical properties of PbO-TeO 2 glasses Slowly cooled glass Rapidly cooled glass Excitons? Kaur et al. J. Non-Cryst. Solids 356(2010)864

41 XRD studies Slowly cooled PbO-TeO 2 glasses Rapidly cooled PbO-TeO 2 glasses Samples are transparent glass-ceramics containing PbTe 3 O 8 & PbTeO 3 phases

42 Raman studies in PbO-TeO 2 and ZnO-TeO 2 glasses Conversion of TeO 4 TeO 3 units Intensity of peak at 662 cm -1 decreases relative to peak at cm -1 Kaur et al. J. Non-Cryst. Solids 356(2010)864

43 WO 3 -TeO 2 Glasses: XRD patterns Density increases T g maxima at 20 mol% WO 3 Raman Spectra W-O vibrations

44 Nb 2 O 5 -TeO 2 glasses

45 Thermal properties of Glasses very different from Crystals C p ~ T 3 in crystals at low temperatures Debye s Law In amorphous solids we observe excess of C p Between 0-1 Kelvin, C p ~ T & Thermal Conductivity K ~ T 2 in glasses Actually C p ~ T 1+δ, δ~ (superlinear) and, K ~ T 2- ε, ε ~ (sub-quadratic) Plateau observed in K between 3 and 15 Kelvin. C p also exhibits a broad maxima in this temperature range when C p /T 3 is plotted Vs T

46 Thermal Conductivity ~ Specific Heat Capacity x Debye Sound Velocity x Mean Free Path Plateau in K subdued in fragile glasses R.C. Zeller & R.O. Pohl, PRB(1971)

47 Low Temperature Specific Heat Capacity Measurements in Borate, Silicate and Tellurite Glasses BOSON PEAK Boson Peak Due To Heterogeneities in Glass?

48 Boson Peak Sharper and more Intense in Purely Glassy Phase

49 Boson Peak Sharper and more Intense in Purely Glassy Phase Boson peak more pronounced Fully In Cerammed Glass than Lead in Glass Silicate Ceramics Continues To Show Glassy Behavior Lower Specific Heat Capacity in glassy phase at Higher Temperature

50 Indo-French Collaboration for: Solving Challenging Problems in Glasses: Glass Formation & Nature of Glass Transition. Phase Separation-Polyamorphism. Structural Heterogeneities in Glasses and their Melts. Glass Structure and Correlation with their optical, mechanical and thermal properties. Low Temperature thermal properties of glasses. Effects of high pressures on glasses. Heterogeneities can functionalize glasses for Applications In High Strength and Optical Materials and Non-Linear Optics.

51 Acknowledgements: Ph.D. students :Anu Bajaj, Arshpreet Kaur and Amanpreet Saini and Nimal Kaur. Dr. P.S. R. Krishna, BARC, Mumbai, India for High-Q Neutron Diffraction Dr. R. Rawat and Dr. V. Sathe, UGC-DAE-CSR, Indore India for Low Temperature Thermal Properties Measurements and Raman Studies. Professor Scott Kroeker, University of Manitoba, Canada Professor J. W. Zwanziger, Dalhousie University, Canada and Dr. Banghao Chen, Florida State University, USA: NMR Studies.