Thermodynamically stable skyrmion lattice at low temperatures in a bulk crystal of lacunar spinel GaV4Se8
Abstract
The magnetic field-temperature (H -T ) phase diagram of a lacunar spinel GaV4Se8 is determined by means of ac magnetic susceptibility and magnetoelectric measurements on single crystals and classical Monte Carlo simulation. GaV4Se8 is pyroelectric below the structural phase transition temperature TS=41 K and magnetically ordered below TC=17.5 K . Ac magnetic susceptibility measurement has revealed that GaV4Se8 undergoes successive magnetic phase transitions with increasing applied magnetic field. Each phase is assigned to cycloidal, skyrmion lattice, and forced ferromagnetic phases. Both cycloidal and skyrmion-lattice magnetic orders induce electric polarization up to around 10 μ C/m 2 compared with ferromagnetic order, suggesting a spin-driven magnetoelectric nature in GaV4Se8 . The skyrmion lattice phase seems to be stable down to T =2 K and up to μ0H =370 mT . This enhanced stability of skyrmion lattice in GaV4Se8 compared with GaV4S8 may provide a key to understanding the formation mechanism of the skyrmion lattice.
- Publication:
-
Physical Review B
- Pub Date:
- May 2017
- DOI:
- 10.1103/PhysRevB.95.180410
- Bibcode:
- 2017PhRvB..95r0410F