Commensurate and incommensurate magnetic structures of UNiGe

Journal Article · Sun Sep 01 04:00:00 EDT 1996 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.54.7201· OSTI ID:385375

Nakotte, H ^[1]; Purwanto, A ^[1]; Robinson, R A ^[1]; Tun, Z ^[2]; Prokes, K ^[3]; Larson, A C ^[1]; Havela, L; Sechovsky, V ^[4]; Maletta, H ^[5]; Brueck, E; de Boer, F R ^[3]

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1. Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
2. Chalk River Laboratories, Atomic Energy of Canada Limited, Chalk River, Ontario, Canada, K0J 1J0 (CANADA)
3. Van der Waals-Zeeman Institute, University of Amsterdam, Valckenierstraat 65, 1018 XE Amsterdam (The Netherlands)
4. Department of Metal Physics, Charles University, 12116 Prague 2, (Czech Republic)
5. Hahn-Meitner Institute, 14109 Berlin (Germany)

A single crystal of the orthorhombic intermetallic compound UNiGe has been studied at both steady-state and pulsed neutron sources in its commensurate ({ital T}{lt}41.5 K) and incommensurate (41.5{lt}{ital T}{lt}51 K) magnetic phases. The ordering wave vector in both phases is {bold q}=(0,{delta},{delta}), with {delta}=1/2 in the commensurate phase. {delta} is temperature dependent in the incommensurate phase, increasing from 0.35 at 50 K to 0.37 at 44 K. Irreducible representation theory is used to discuss the possible moment configurations in real space, and least-squares refinement gives a moment of 0.36{mu}{sub {ital B}} at 46 K, compared with 0.96{mu}{sub {ital B}} at 20 K. While symmetry allows moment components along all three Cartesian directions, previous unpolarized-neutron-diffraction data had been analyzed in terms of a collinear arrangement of moments in the {ital b}-{ital c} plane. Polarized neutron diffraction in the low-temperature commensurate phase shows that it is noncollinear, with an additional {ital x} component to the uranium moment, and there is some evidence that this is also the case in the incommensurate phase. The polarized-neutron measurement gives a canting angle, with respect to the {ital b}-{ital c} plane, of 17{plus_minus}4{degree}. The observed {mu}{sub {ital x}} components are discussed in terms of bonding of the 5{ital f}-electron orbitals with the surrounding ligands. {copyright} {ital 1996 The American Physical Society.}

• OSTI ID: 385375
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 10 Vol. 54; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
COMMENSURATE-INCOMMENSURATE TRANSFORMATIONS
GERMANIUM COMPOUNDS
MAGNETIC PROPERTIES
MONOCRYSTALS
NEUTRON DIFFRACTION
NICKEL COMPOUNDS
ORTHORHOMBIC LATTICES
PHASE STUDIES
TEMPERATURE RANGE 0013-0065 K
TERNARY COMPOUNDS
URANIUM COMPOUNDS