Open AccessPressure induced semimetallic B2 phase of alkaline earth tellurides
Author(s) -
Lavanya Kunduru,
Suresh Sripada,
S. C. Rakesh Roshan,
N. Yedukondalu,
M. Sainath
Publication year - 2020
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/1495/1/012041
Subject(s) - semimetal , dirac (video compression format) , phase (matter) , electronic band structure , condensed matter physics , density functional theory , band gap , semiconductor , fermi level , coupling (piping) , electronic structure , phase transition , fermi surface , alkaline earth metal , topology (electrical circuits) , materials science , chemistry , physics , computational chemistry , quantum mechanics , alkali metal , optoelectronics , composite material , organic chemistry , superconductivity , mathematics , combinatorics , neutrino , electron
We report pressure induced structural, topological quantum phase transitions and Fermi surface topology in MTe (M = Ca, Sr, Ba) compounds under high pressure using first principles calculations based on density functional theory. MTe compounds undergo a first order structural phase transition from NaCl-type (B1) to CsCl-type (B2) phase at 24.2, 14.7, 4.9 GPa respectively and are consistent with the experimental observations. Electronic structure of MTe compounds were calculated using new parameterization of Tran Blaha-modified Becke Johnson (TB-mBJ) potential and the obtained band gaps are improved over LDA/GGA functionals. The three compounds under investigation are indirect band gap semiconductors at ambient conditions. Under high pressure, B2 phase of (Ca/Sr)Te and BaTe are found to be node-line and Dirac semimetals, respectively without inclusion of spin-orbit coupling.