International Journal of Innovative Technology and Exploring Engineering (IJITEE) ISSN: 2278-3075, Volume-9 Issue-1, November 2019 Compositional Effect of Barium Ions (Ba2+) on Ultrasonic, Structural and Thermal Properties of LeadBorate Glasses R. Ezhil Pavai, P. Sangeetha, L. Balu preparing glasses by alone, it is used to behave as a network Abstract: Glasses of the formula 68B2O3-(32-x)PbO-xBaO (0≤ x former/modifier in glass matrices and also addition to glass ≤ 12) were synthesized by standard melt quench technique and network, stabilizes the glass [8, 9]. Moreover doping with investigated their properties using XRD, ultrasonic, FT-IR and barium ions, these glasses show low dispersion, co-efficeint DTA studies. No sharp peaks are existing in the XRD spectra and of thermal expansion and melting point as well as high the broad halo appeared around 2θ≈30o, which reflects the characteristics of amorphous nature. Density decreases due to the refraction and electric resistance [10, 11]. The authors were replacement of higher molar mass by lower molar mass. The attempted to synthesis and characterize the BaO doped B2O3 ultrasonic velocity varies with the gradual substitutions of barium – PbO glasses by using several techniques such as XRD, ions in leadborate host glass matrix. The variations in elastic ultrasonic velocity, DTA and FT-IR. moduli such as L, G, K and E), Poisson’ sratio(), acoustic impedance(Z), microhardness (H) and Debye temperature II. EXPERIMENTAL (θD)were observed which resulted in compact glasses. The functional groups of prepared glasses were studied by FTIR A. Sample preparation analysis and BO4 structural units enhanced with decreasing BO3 Glasses of formula 68B2O3-(32-x)PbO-xBaO were structural units. Characteristic temperatures of DTA increase synthesized by the standard melt-quench technique. BaO because of the higher bond strength of barium ions and also was increased form 0 to 12mol%. While the content of PbO strength of the glasses. was decreased form 32 to 20%. The pure boron trioxide (B2O3), lead monoxide (PbO) and barium oxide (BaO) were Kwywords :BPBa glasses, DTA, FTIR, Ultrasonic velocity mixed with each other by continuous grinding to get a fine powder. The ground mixtures were taken in the crucible and I. INTRODUCTION placed in a high temperature furnace at 900 oC. As a result, The borate glasses are studied intensively due to the mixture was melted homogeneously. The bubble free existence of their structural properties. Besides, these liquid was casted into prewarmed copper mould to obtain glasses are keenly attracted by research community because the glass samples of dimension 6mm thickness and 10mm of their unique and novel properties for instance wide range diameter The prepared glasses were sintered at 450 oC for 3 formation regions, low melting point, high radiation hours in order to remove internal stresses which shielding properties and so on [1, 2]. PbO can play dual caused during sample preparation process. Then the glasses role in the glass matrices, it exists as a modifier in were polished using a polishing machine and the polished octahedral (PbO6) structural units and as a former in glasses are ready for ultrasonic characterization. The 2+ tetrahedral (PbO4) form. The content of Pb ions in nomenclature and elemental composition of the prepared tetrahedral and octahedral positions developing in the glass glasses are tabulated in Table 1. matrices are strongly depending upon glass formers, the The XRD technique (PAN Alytical x’ Pert PRO Powder field strength and the ion size in the structure of the glass X-ray Diffractometer, 15kVA UPS support) has been [3]. Last few decades, many attempts were made in performed in order to study the crystal structure of prepared order to study the significant of PbO in the glass matrices glasses. The density of the prepared glasses was estimated using various methods and techniques [4-6]. using Archimedes principle with water; it is used as a In the present investigation, binary B2O3–PbO glass is floatation medium. The Pulse – Echo Overlapping method choosing as a parent glass because it exhibits low rate of was used to study the longitudinal and shear velocities of the crystallization, high moisture resistance, refractive index and glasses at 303K with 10MHz X-cut and Y-cut transducers. density. Leadborate glasses doped with alkaline earth metal These transducers were in contact with each of the samples oxide have potential applications in various domains of by a couplet to ensure no space between the transducers and modern technology and show an interesting behaviour [7]. the glass. By giving sustained pressure on the probe, the Though barium oxide is not suitable for echo waveforms were received and stored in the memory. Velocity is calculated using the relation, U=2d/t (1) Revised Manuscript Received on November 05, 2019. R. EzhilPavai,PG and Research Department of Physics, The mechanical and elastic properties have been Thiru Kolanjiappar Govt. Arts College, Virddhachalam, understand from the following relations, Tamil Nadu, India. Email: [email protected] P. Sangeetha, Department of Physics, Annamalai University, M Annamalai Nagar, Tamil Nadu, India. Molar Volume = (2) Email: [email protected] ρ L. Balu, PG and Research Department of Physics, Govt. Arts College, C. Mutlur, Tamil Nadu, India. Email: [email protected] Published By: Retrieval Number: A4268119119/2019©BEIESP 481 Blue Eyes Intelligence Engineering DOI: 10.35940/ijitee.A4268.119119 & Sciences Publication Compositional Effect of Barium Ions (Ba2+) on Ultrasonic, Structural and Thermal Properties of LeadBorate Glasses 2 which will define the crystal structure of the prepared Longitudinal Modulus= ρ U (3) sample. In other words, it is also interpreted in terms of 2 rivalry between the mass and size of the various structural Shear modulus=ρ Us (4) units takes place in the glass. The gradual replacement of lead ions by barium ions and the corresponding variations of Bulk Modulus= 4 (5) L G density and molar volume cause a monotonic decrease. 3 Density varies from 3.9003× 103 kgm-3 to 3.7492 ×103 kgm- 3 -6 3 Young’s Modulus=(1 +)2G (6) and molar volume varies from 30.43 × 10 m /mol to 29.44×10-6m3/mol. Acoustic Impedance= Uℓ (7) 3.94 Poisson’s Ratio= L 2G (8) 3.9 2(L G) ) 3 - 3.86 E kgm 3.82 3 Microhardness = (1 – 2) (9) 6(1 ) (10 3.78 ρ 1 3.74 Debye Temperature = h 9N 3 (10) Um 3.7 K 4Vm 0 3 6 9 12 15 where K is the Boltzmann’s constant, N is the Avogadro’s BaO mol% number, h is Planck’s constant and Vm, molar volume of the prepared glasses. The mean sound velocity estimated by Fig. 2. Deviation of density with BaO mol% 1 1 2 1 3 Um = (11) 3 3 31 3 U s U 30.6 /mol) The FTIR spectrum were studied for the powdered 3 m 6 glasses at room temperature in the wavenumber range 400- - 30.2 -1 -1 (10 4000 cm with a resolution of 4 cm by RX1 Perkin Elemer 29.8m V FTIR spectrometer using KBr pellet technique. The thermal 29.4 transition parameters such as Tg, Tc and Tm of these glasses were determined by Differential Thermal Analyser 29 NETZSCH-STA449FS JUPITER instrument in inert gas 0 3 6 9 12 15 BaO mol% atmosphere at a heating rate of 20°C per minute. Fig. 3. Deviation of molar volume with BaO mol% III. RESULTS AND DISCUSSION This variation is occurred due to the replacement of heavier cation by lighter and the values of density is well A. X-ray diffraction understandable from the deviation in the molar mass of the The synthesized glasses were bubble free, transparent added components and the molar mass of PbO (223.2 g/mol) and homogeneous. The non-existence of Bragg’s peak in the is heavier than BaO (153.33 g/mol) causes decrease in spectrograms (Fig.1) clearly indicated that the studied density. Similar trends also followed by many researchers samples are non-crystalline and homogeneous in nature. [13, 15]. Generally, density and molar volume revealed an Moreover, the board humps around 2휃 indicate that there is opposite attitude. But in the present report, similar trend of a existence of short range order in the glasses [12]. variation is also observed in the molar volume and this indicates that a more BO4 units linked to divalent barium ions are much denser, occupying less volume. Hence the incorporation of BaO in the lead borate glass system contracts the glass network, increases the rigidity of the glasses resulting in a close – packing atomic structure. Fig. 1. XRD pattern of BPBa glasses B. Density and molar volume Figs. 2 and 3 show the variation of molar volume and density of barium oxide concentration in the prepared glasses. Density of solids is one of the simplest physical parameters to measure. However, it is more informative Published By: Retrieval Number: A4268119119/2019©BEIESP 482 Blue Eyes Intelligence Engineering DOI: 10.35940/ijitee.A4268.119119 & Sciences Publication International Journal of Innovative Technology and Exploring Engineering (IJITEE) ISSN: 2278-3075, Volume-9 Issue-1, November 2019 Table- I: Values of longitudinal velocity (Ul), shear velocity (Us) and elastic moduli (L & G) -1 Longitudinal Shear Sample Composition in mol% Ultrasonic velocity ms modulus modulus code B2O3 PbO BaO Longitudinal(Ul) Shear(Us) L (GPa) G (GPa) BP 68 32 0 4260.2 2251.4 70.78 19.76 BPBa03 68 29 3 4388.2 2373.0 74.62 21.80 BPBa06 68 26 6 4559.3 2513.1 79.62 24.19 BPBa09 68 23 9 4694.6 2619.7 83.72 26.07 BPBa12 68 20 12 4835.7 2750.2 87.67 28.35 C.