Giant magnetoresistance and magnetic phase diagram of UNiGa

Journal Article · Mon Apr 01 00:00:00 EST 1996 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.362010· OSTI ID:281714

Prokes, K; Brueck, E; de Boer, F R; Mihalik, M; Menovsky, A ^[1]; Burlet, P ^[2]; Mignot, J M ^[3]; Havela, L; Sechovsky, V ^[4]

---

1. Van der Waals-Zeeman Institute, University of Amsterdam, 1018 XE Amsterdam (The Netherlands)
2. DRFMC-SPH/LIH CEN Grenoble, 85X-38041 Grenoble Cedex (France)
3. Laboratoire Leon Brillouin, CEA/CNRS, CE Saclay, 911 91 Gif-Sur-Yvette Cedex (France)
4. Department of Metal Physics, Charles University, 12116 Prague 2, (Czech Republic)

As a result of combined magnetization, specific heat, electrical resistivity, and neutron-scattering studies on single crystals, we present a complex magnetic phase diagram of UNiGa that exhibits several antiferromagnetic (AF) phases below {ital T}{sub {ital N}}=39 K. A relatively low magnetic field ({approximately}1{endash}1.5 T) applied along the {ital c}-axis induces metamagnetic transitions from the zero-field AF structures to an uncompensated AF and/or to a ferromagnetic (F) phase. All the magnetic structures are collinear (uranium magnetic moments parallel to the {ital c}-axis of the hexagonal structure). They consist of F basal-plane sheets which are coupled along {ital c} in various ways. The strongly anisotropic magnetism in UNiGa causes anisotropy of the electrical resistivity. The magnetic phase transitions are reflected in pronounced resistivity anomalies especially for current along the {ital c}-axis. The metamagnetic transitions are accompanied by giant magnetoresistance (GMR) effects which can be correlated with respective changes of the magnetic periodicity. This implies an important feature of the mechanism responsible for GMR phenomena in UNiGa. The strong resistance enhancement in the paramagnetic range when approaching {ital T}{sub {ital N}} is connected with AF short-range ordering with propagation along the {ital c}-axis. {copyright} {ital 1996 American Institute of Physics.}

• OSTI ID: 281714
• Report Number(s): CONF-951101-; ISSN 0021-8979; TRN: 9608M0151
• Journal Information: Journal of Applied Physics, Vol. 79, Issue 8; Conference: 40. conference on magnetism and magnetic materials, Philadelphia, PA (United States), 6-9 Nov 1995; Other Information: PBD: Apr 1996
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
URANIUM COMPOUNDS
MAGNETORESISTANCE
NICKEL COMPOUNDS
GALLIUM COMPOUNDS
MAGNETIC MATERIALS
MAGNETIZATION
SPECIFIC HEAT
PHASE DIAGRAMS
PHASE TRANSFORMATIONS
ELASTIC SCATTERING
NEUTRON BEAMS
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE 0000-0013 K
TEMPERATURE RANGE 0013-0065 K
TEMPERATURE RANGE 0065-0273 K