20-22 May 2015
Asia/Bangkok timezone
The Centennial Celebration of General Relativity Theory and 80 Years of Thai Physics Graduate

Revealing an unusual transparent phase of superhard iron tetraboride under high pressure

20 May 2015, 14:15
15m
Hemingways' Lounge ()

Hemingways' Lounge

Oral presentation Condensed Matter Physics Condensed Matter Physics

Speaker

Mr Komsilp Kotmool (Department of Physics, Mahidol Wittayanusorn School, Nakhon Pathom, Thailand 73170; Department of Physics, Faculty of Science, Chulalongkorn University, Bangkok, Thailand 10330)

Description

First principles–based electronic structure calculations of superhard iron tetraboride (FeB$_4$) under high pressure have been undertaken in this study. Starting with a “conventional” superconducting phase of this material under high pressure leads to an unexpected phase transition toward a semiconducting one. This transition occurred at 53.7 GPa, and this pressure acts as a demarcation between two distinct crystal symmetries, metallic orthorhombic and semiconducting tetragonal phases, with Pnnm and I4$_1$/acd space groups, respectively. In this work, the electron–phonon coupling-derived superconducting Tc has been determined up to 60 GPa and along with optical band gap variation with increasing pressure up to 300 GPa. The dynamic stability has been confirmed by phonon dispersion calculations throughout this study.

Primary author

Mr Komsilp Kotmool (Department of Physics, Mahidol Wittayanusorn School, Nakhon Pathom, Thailand 73170; Department of Physics, Faculty of Science, Chulalongkorn University, Bangkok, Thailand 10330)

Co-authors

Dr Gou HUIYANG (Geophysical Laboratory, Carnegie Institution for Science, Washington, DC 20015) Prof. Ho-kwang MAO (Geophysical Laboratory, Carnegie Institution for Science, Washington, DC 20015) Mr Jonas ANVERSA (Departamento de Física, Universidade Federal de Santa Maria, Santa Maria, Rio Grande do Sul, Brazil 97105-900) Prof. Luo WEI (Condensed Matter Theory Group, Department of Physics and Astronomy, Uppsala University, Uppsal, Sweden S-75120) Prof. Paulo Cesar PIQUINI (Departamento de Física, Universidade Federal de Santa Maria, Santa Maria, Rio Grande do Sul, Brazil 97105-900) Prof. Rajeev AHUJA (Condensed Matter Theory Group, Department of Physics and Astronomy, Uppsala University, Uppsala, Sweden S-75120) Sudip CHAKRABORTY (Condensed Matter Theory Group, Department of Physics and Astronomy, Uppsala University, Uppsala, Sweden S-75120) Prof. Tae-won KANG (Quantum Functional Semiconductor Research Center, Dongguk University, Chung gu, Seoul, Korea 100-715) Mr Thanayut KAEWMARAYA (Condensed Matter Theory Group, Department of Physics and Astronomy, Uppsala University, Uppsala, Sweden S-75120) Thiti BOVORNRATANARAKS (Department of Physics, Faculty of Science, Chulalongkorn University, Bangkok, Thailand 10330)

Presentation Materials

There are no materials yet.