Flor Quiroga Bañuelos1,David Hinojosa1,Isaías Rodríguez1,Alexander Valladares2,Renela Valladares2,Ariel Valladares1
Universidad Nacional Autónoma de México, Instituto de Investigaciones en Materiales1,Universidad Nacional Autónoma de México, Facultad de Ciencias2
Flor Quiroga Bañuelos1,David Hinojosa1,Isaías Rodríguez1,Alexander Valladares2,Renela Valladares2,Ariel Valladares1
Universidad Nacional Autónoma de México, Instituto de Investigaciones en Materiales1,Universidad Nacional Autónoma de México, Facultad de Ciencias2
The physicochemical properties of amorphous metals and bulk metallic glasses, when subjected to extreme conditions such as low temperatures or high pressures, make them attractive materials for important technological applications [1]. To fully exploit their benefits, it is necessary to understand the electronic and vibrational contributions to their thermodynamic properties, and first-principles calculations have helped to elucidate the physics of this complex materials. Recently, we explored the effects of negative pressures on the superconducting transition temperatures of amorphous Bismuth through the <i>ab initio</i> calculation of its electronic structure [2]. Now we will go into studying the thermodynamic properties of this system by calculating the vibrational densities of states (vDoS) using an <i>ab initio </i>approach. Specifically, in this work we calculate the vDoS, heat capacity and enthalpy for 3 amorphous samples, two of them subjected each to a positive and to a negative pressure. The amorphous samples were generated by <i>ab initio</i> molecular dynamics and our <i>undermelt-quench method</i> [3] applied to supercells of 216 atoms with densities: 10.89, 9.81, and 8.91 g cm<sup>-3</sup> corresponding to a volume of 90%, 100% and 110% of the original volume, respectively. Results will be presented and discussed.<br/><br/>[1] D. C. Hofmann, R. Polit-Casillas, S. N. Roberts, J.-P. Borgonia, R. P. Dillon, E. Hilgemann, <i>et al., </i><i>Castable Bulk Metallic Glass Strain Wave Gears: Towards Decreasing the Cost of High-Performance Robotics. </i>Scientific Reports <b>6</b> (2016), 37773.<br/>[2] F. B. Quiroga Bañuelos, D. Hinojosa-Romero, I. Rodríguez, A. Valladares, R. M. Valladares, A. A. Valladares, Poster QT11.06.02 - <i>Superconductivity in Amorphous Bismuth at Negative Pressures</i>, 2022 MRS Spring Meeting & Exhibit.<br/>[3] A. A. Valladares, <i>A new approach to the ab initio generation of amorphous semiconducting structures. Electronic and vibrational studies</i>, Glass Materials Research Progress, 2008, pp. 61-123. Editor: Jonas C. Wolf and Luka Lange, Nova Science Publishers, Inc. ISBN 978-1-60456-578-2.