Phase Transformations in Ceramics: Science and Applications: Poster Session
Program Organizers: Pankaj Sarin, Oklahoma State University; Scott Mccormack, University Of California, Davis; Waltraud Kriven, University of Illinois at Urbana-Champaign; Theresa Davey, Bangor University; Sanjay V. Khare, University of Toledo
Monday 5:00 PM
October 10, 2022
Room: Ballroom BC
Location: David L. Lawrence Convention Center
D-23: Environmental Conical Nozzle Levitator Equipped with Dual Lasers: Fox Thorpe1; Elizabeth Sobalvarro Converse2; Jesus Rivera2; Harry Charalambous2; Scott McCormack3; 1iversity of California, Daivs; 2Lawrence Livermore National Laboratory; 3University of California, Daivs
A levitation device equipped with environmental controls and oxygen mitigation has been used to analyze molten samples using laser heating. This device uses two lasers to enable heating of various high temperature materials: 400W CO2 laser (10.6µm wavelength) and 500W Ytterbium Fiber laser (1.07µm wavelength). The system uses a vacuum pump, gas scrubber, and ultra-high pure Argon to mitigate reactions. The temperature is determined using two single-color laser pyrometers at 0.9µm (750–3500°C) and 0.65µm (750 – 5000°C). This system is designed to determine the melting point of 3mm diameter spherical samples of various metals (Ni, Nb, Ta, Ti, W), oxides (Al2O3, HfO2, Ta2O5, ZrO2, TiO2, Nb2O5), and diborides (TiB2, NbB2, ZrB2, HfB2, TaB2). The melting point was determined by analyzing the cooling curve created from heating the samples above the melting point and observing the recalescence as the sample solidifies. Corrections were made for sample emissivity to ensure temperature accuracy.
D-24: Relationship of Bonding Strength with Stability of Ternary Oxide Phases of MgSnO3: A First-principles Study: Bishal Dumre1; Sanjay Khare1; 1University of Toledo
We have investigated the Ilmenite, Perovskite and LiNbO3 type crystal structures of ternary oxide MgSnO3 by ab-initio methods using density functional theory (DFT) and beyond. We deduce that MgSnO3 in Ilmenite and Perovskite structures are mechanically stable but dynamically unstable, however, LiNbO3 type is both mechanically and dynamically stable. Vibrational stability in MgSnO3 expects some distortion in octahedra because of the strength of bonding between the atom pairs Sn-O in LiNbO3 type structure. Similarly, Ilmenite and Perovskite structures demand a higher number of Mg-Sn and (Mg-Mg, Sn-Sn, O-O and Mg-O) bonds respectively. Ilmenite and LiNbO3 type structures can be utilized as window layers highlighting a large bandgap of 5.22 eV and 3.88 eV respectively, in addition to a lower absorption coefficient and reflectivity. Likewise, Perovskite structure with a bandgap of 2.55 eV can be used as an absorber layer that captures green light of solar irradiation in tandem solar cells.