Variations of magnetic properties of UGa.sub.2./sub. under pressure

0448053 - FZÚ 2016 RIV US eng J - Journal Article
Kolomiets, A. - Griveau, J.C. - Prchal, J. - Andreev, Alexander V. - Havela, L.
Variations of magnetic properties of UGa₂ under pressure.
Physical Review. B. Roč. 91, č. 6 (2015), "064405-1"-"064405-10". ISSN 1098-0121
R&D Projects: GA ČR GAP204/12/0150; GA ČR(CZ) GAP204/10/0330
Institutional support: RVO:68378271
Keywords : uranium intermetallics * ferromagnetism * high pressure
Subject RIV: BM - Solid Matter Physics ; Magnetism
Impact factor: 3.736, year: 2014

Electrical resistivity R(T) of the 5f-ferromagnet UGa2 was investigated on single crystals as a function of pressure and magnetic field. Under quasi-hydrostatic pressure the Curie temperature monotonously increases from TC = 124 K up to 154 K at p = 14.2 GPa after which it turns down steeply and reaches 147 K at p = 15.2 GPa. At 20 GPa the compound is already nonmagnetic. This dramatic variation is compatible with the exchange interactions mediated by the 5f hybridization with the non-f states. The external pressure first enhances the exchange coupling of the 5f moment but eventually suppresses the magnetic order by washing out the 5f moments. Such a two-band model is adequate for the weakly delocalized 5f states. The external pressure gradually suppresses the spin-disorder resistivity, which reaches very high ρ values (300 microOhmcm) above TC in UGa2.
Permanent Link: http://hdl.handle.net/11104/0249787