Surface and bulk magnetic properties of pyrite NiS{sub 2}: Magnetization and neutron-scattering studies

Journal Article · Tue Aug 01 04:00:00 EDT 1995 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.52.3555· OSTI ID:83933

Thio, T; Bennett, J W ^[1]; Thurston, T R ^[2]

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1. NEC Research Institute, 4 Independence Way, Princeton, New Jersey 08540 (United States)
2. Brookhaven National Laboratory, Upton, New York 11973 (United States)

In pyrite-structure antiferromagnetic NiS{sub 2}, the magnetic susceptibility {chi}({ital T}) shows downward curvature above the Neel transition ({ital T}{sub {ital N}1}=39.2 K), suggesting that magnetic correlations persist to {ital T}=400 K. However, neutron-scattering measurements indicate that the bulk magnetic behavior above {ital T}{sub {ital N}1} is conventional. We present evidence that the unusual temperature dependence of {chi}({ital T}) arises from a surface contribution. At {ital T}{sub {ital N}2}=29.75 K a transition occurs to a weakly ferromagnetic state, accompanied by a small structural distortion. We show that this distortion is not tetragonal as suggested previously, but is most likely rhombohedral. Below {ital T}{sub {ital N}2}, {chi}({ital T}) is anisotropic; our data suggest that in this range {chi}({ital T}) is dominated by next-nearest-neighbor exchange interactions.

• Research Organization: Brookhaven National Laboratory
• DOE Contract Number: AC02-76CH00016
• OSTI ID: 83933
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 5 Vol. 52; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ANISOTROPY
MAGNETIC PROPERTIES
MAGNETIC SUSCEPTIBILITY
MAGNETIZATION
NEEL TEMPERATURE
NEUTRON DIFFRACTION
NICKEL SILICIDES
SURFACE PROPERTIES
TEMPERATURE DEPENDENCE