SKM 2023 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 21: Correlated Electrons: Electronic Structure Calculations
TT 21.2: Vortrag
Dienstag, 28. März 2023, 09:45–10:00, HSZ 201
Distortion and pressure induced phase transitions in double perovskite La2CoTiO6 — •Sromona Nandi1, Ashis K. Nandy2, and Rudra Sekhar Manna1 — 1Department of Physics, Indian Institute of Technology Tirupati, Tirupati 517619, AP, India — 2School of Physical Sciences, National Institute of Science Education and Research, An OCC of Homi Bhabha National Institute, Jatni-752050, India
We study the density-functional theory spin-polarized electronic structure calculations for a double perovskite La2CoTiO6 where the magnetic moment comes from the Co2+ as Ti is in 4+ state. Due to the rotation and volume mismatch between the TiO6 and CoO6 octahedra (∠Co-O-Ti is 151–153∘), the system is distorted at ambient pressure. The Co-moments align antiferromagnetically at low temperature and show an insulating transport property with a band gap of 1 eV, consistent with the experiment [1]. With the removal of distortion, i.e., ideal undistorted structure (∠Co-O-Ti is 180∘) shows a metallic behavior. Such metallic state can also be achieved with the application of hydrostatic pressure on the distorted structure accompanied by the quenching of Co-moment in the metallic phase which can be understood by the shifting of the exchange splitting of the Co 3d orbitals at the Fermi level. In addition, atomic projected density of states analysis of the Co sublattices shows an interesting half-metallic like intermediate state which could be interesting for spintronics applications.
[1] K. L. Holman et al., J. Solid State Chem. 180, 75 (2007)