Leonid Sandratski: Magnetic phase transitions induced by pressure and magnetic field: the case of antiferromagnetic USb2
Venue: Ke Karlovu 5, Prague 2 | City: Prague 2
We have a pleasure to invite you to attend the joint seminar
of the Department of Condensed Matter Physics (DCMP)
and the Materials Growth and Measurement Laboratory (MGML) http://mgml.eu.
Magnetic phase transitions induced by pressure and magnetic field: the case of antiferromagnetic USb2
lecture given by:
Max-Planck-Institute of Microstructure Physics, Weinberg 2, 06120 Halle, Germany
The seminar takes place in the lecture room F2
of the Faculty of Mathematics and Physics, Ke Karlovu 5, Praha 2
on Wednesday, 5.12. 2018 from 14:10
On behalf of the DCMP and MGML
Fascinating phase transformations under applied pressure and magnetic field are currently attracting much research attention. Recent experiments have shown that applications of the pressure or magnetic field to the USb2 compound induce the transformations of the ground-state antiferromagnetic (AFM) up-down-down-up structure to, respectively, ferromagnetic (FM) and ferrimagnetic configurations. Remarkably, the magnetic critical temperature of the FM state, induced by pressure, is more than two times smaller than the Neel temperature of the ground state. We performed density-functional theory (DFT) DFT+U studies to reveal the origin of the unusual ground-state of the system and the driving mechanisms of the phase transitions. We investigate both the magnetic anisotropy properties and the parameters of the interatomic exchange interactions. To study pressure-induced effects we carry out calculations for reduced volume and demonstrate that the AFM-FM phase transformation indeed takes place but depends crucially on the peculiar features of the magnetic anisotropy. We also explain why the magnetic field that couples directly to the magnetic moments of atoms leads to the phase transition to the ferrimagnetic state whereas the pressure that does not couple directly to magnetic moments results in the FM structure. Summarizing, we suggest a physical picture able to explain in a consistent way the unusual variety of the properties of the antiferromagnetic USb2.
- Wednesday, 05 December 2018 14:10 - 15:10