High Pressure Collapse of Magnetism in Fe{sub 0.94}O: Moessbauer Spectroscopy Beyond 100GPa

Journal Article · Mon Dec 01 04:00:00 EST 1997 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.79.5046· OSTI ID:577992

Pasternak, M P ^[1]; Pasternak, M P; Taylor, R D ^[2]; Jeanloz, R; Li, X; Nguyen, J H ^[3]; McCammon, C A ^[4]

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1. School of Physics and Astronomy, Tel Aviv University, 69978 Tel Aviv (Israel)
2. MST-10, MS-K764, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
3. Department of Geology and Geophysics, University of California, Berkeley, California 94720 (United States)
4. Bayerisches Geoinstitut, Universitaet Bayreuth, D-95440 Bayreuth (Germany)

First studies of Moessbauer spectroscopy to pressures above 100GPa are reported. The magnetic state of Fe{sub 0.94} O was investigated to 120GPa at T{le}300 K . At 300K a diamagnetic {ital low-spin } (LS) state of Fe{sup 2+} is detected at 90GPa; its abundance increases with P. The gap between the {sup 5}T{sub 2g} {ital high-spin} ground state and the {sup 1}A{sub 1g} LS {ital excited state} decreases with increasing P and at 120GPa the LS species, first observed at 70K, is fully converted at {approximately}450 K . The magnetic collapse of Fe{sub 1{minus}x}O is an isochoric, second-order transition resulting from a gradual increase in the crystal-field with increasing pressure. {copyright} {ital 1997} {ital The American Physical Society}

• OSTI ID: 577992
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 25 Vol. 79; ISSN 0031-9007; ISSN PRLTAO
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
66 PHYSICS
CRYSTAL FIELD
ELECTRIC CONDUCTIVITY
ENERGY GAP
IRON OXIDES
MAGNETISM
MOESSBAUER EFFECT
PHASE TRANSFORMATIONS
PRESSURE DEPENDENCE
SPIN ORIENTATION
SYNCHROTRON RADIATION
VERY HIGH PRESSURE