Magnetic gap excitations in a one-dimensional mixed spin antiferromagnet Nd{sub 2}BaNiO{sub 5}

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

DOI:https://doi.org/10.1103/PhysRevB.54.7210· OSTI ID:383173

Zheludev, A; Tranquada, J M; Vogt, T ^[1]; Buttrey, D J ^[2]

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1. Brookhaven National Laboratory, Upton, New York 11973-5000 (United States)
2. University of Delaware, Newark, Delaware 19716 (United States)

Magnetic excitations in a Nd{sub 2}BaNiO{sub 5} powder sample were investigated by inelastic neutron scattering. Well-defined one-dimensional (1D) gap modes were observed {ital above} {ital and} {ital below} the N{acute e}el temperature {ital T}{sub {ital N}}=24 K. In both temperature regimes the measured dynamic structure factor was found to be consistent with that calculated for transverse Haldane gap modes in a quantum-disordered {ital S}=1 linear-chain antiferromagnet. The energy gap does not show any appreciable {ital T} dependence at {ital T}{approx_gt}{ital T}{sub {ital N}}. However, in the ordered phase the spin gap {ital increases}. The observed behavior is totally different from that found in other Haldane gap systems undergoing 3D antiferromagnetic ordering, such as CsNiCl{sub 3}. {copyright} {ital 1996 The American Physical Society.}

• Research Organization: Brookhaven National Laboratory
• DOE Contract Number: AC02-76CH00016
• OSTI ID: 383173
• 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
ANTIFERROMAGNETIC MATERIALS
BARIUM OXIDES
ENERGY GAP
EXCITATION
NEEL TEMPERATURE
NEODYMIUM OXIDES
NEUTRON DIFFRACTION
NICKEL OXIDES
POWDERS
QUATERNARY COMPOUNDS
STRUCTURE FACTORS