Ferrimagnetism in Ni{sub 4}Nb{sub 2}O{sub 9}

Journal Article · Sun Oct 01 04:00:00 EDT 1995 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.52.9595· OSTI ID:249432

Ehrenberg, H; Wltschek, G; Weitzel, H ^[1]; Trouw, F ^[2]; Buettner, J H; Kroener, T ^[3]; Fuess, H ^[1]

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1. Fachgebiet Strukturforschung, Fachbereich Materialwissenschaft, Technische Hochschule Darmstadt, D-64287 Darmstadt (Germany)
2. IPNS Division of the Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States)
3. Forschungszentrum Karlsruhe, Institut fuer Technische Physik, P.O. Box 3640, D-76021 Karlsruhe (Germany)

For the {ital Pbcn} form of nickel diniobate Ni{sub 4}Nb{sub 2}O{sub 9} ferrimagnetic ordering is observed below {ital T}{sub {ital C}}=76.1(1) K. Two models for the magnetic structure result in calculated intensities for the magnetic reflections, which are in satisfying agreement to the data observed in neutron powder diffraction. In both cases the magnetic structure consists of two ferromagnetic sublattices according to the two Ni sites, which are antiparallel to each other. One model belongs to the magnetic symmetry group {ital Pb}{prime}{ital cn}{prime} with the moments aligned parallel [010] and the other one to {ital Pbc}{prime}{ital n}{prime} with the moments parallel [100]. The absolute values of the magnetic moments, constrained to the same value for both sites, are determined to {vert_bar}{mu}{vert_bar}=1.35(5){mu}{sub {ital B}} (60 K) and 1.65(5){mu}{sub {ital B}} (1.5 K) for both models. A compensation temperature of {ital T}{sub comp}=33 K is observed, and the mangnetic properties can be explained by the competition between antiferromagnetic intrasite and intersite couplings using mean field approximation. In the paramagnetic region an averaged magnetic moment of 3.54(5){mu}{sub {ital B}} is derived from the Curie-Weiss constant. These values are in good agreement with the predictions by Hund`s rules for Ni{sup 2+}.

• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 249432
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 13 Vol. 52; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ANTIFERROMAGNETISM
CURIE-WEISS LAW
FERRIMAGNETISM
MAGNETIC MOMENTS
MAGNETIC PROPERTIES
MEAN-FIELD THEORY
NICKEL OXIDES
NIOBIUM OXIDES
SYMMETRY GROUPS