New interface

# Structural, magnetic, and insulator-to-metal transitions under pressure in the GaV4S8 Mott insulator: A rich phase diagram up to 14.7 GPa

1 IMAPEC - Instrumentation, Material and Correlated Electrons Physics
PHELIQS - PHotonique, ELectronique et Ingénierie QuantiqueS : DRF/IRIG/PHELIQS
Abstract : In addition to its promising potential for applications, GaV$_4$S$_8$ shows very interesting physical properties with temperature and magnetic field. These properties can be tuned by applying hydrostatic pressure in order to reveal and understand the physics of these materials. Not only pressure induces an insulator-to-metal transition in GaV$_4$S$_8$ but it also has an interesting effect on the structural and magnetic transitions. Using a combination of AC calorimetry, capacitance, and resistivity measurements under pressure, we determine the evolution of the structural and magnetic transitions with pressure and thus establish the $T-P$ phase diagram of GaV$_4$S$_8$. To detect the insulator-to-metal transition (IMT), we use optical conductivity and DC resistivity measurements and we follow the evolution of the Mott gap under pressure. The structural transition temperature increases with pressure and a second transition appears above 6 GPa indicating a possible new phase with a very small gap. Pressure has a surprisingly very weak effect on the ferromagnetic transition that persists even very close to the IMT that occurs at around 14 GPa, implying that the metallic state may also be magnetic.
Document type :
Journal articles
Domain :

Cited literature [16 references]

https://hal-cea.archives-ouvertes.fr/cea-02496662
Contributor : Julia Mokdad Connect in order to contact the contributor
Submitted on : Tuesday, March 3, 2020 - 11:16:57 AM
Last modification on : Tuesday, September 13, 2022 - 4:18:23 PM
Long-term archiving on: : Thursday, June 4, 2020 - 2:27:28 PM

### File

Files produced by the author(s)

### Citation

J. Mokdad, G. Knebel, C. Marin, J.-P. Brison, V. Ta Phuoc, et al.. Structural, magnetic, and insulator-to-metal transitions under pressure in the GaV4S8 Mott insulator: A rich phase diagram up to 14.7 GPa. Physical Review B, 2019, 100 (24), pp.245101. ⟨10.1103/PhysRevB.100.245101⟩. ⟨cea-02496662⟩

Record views