Magnetic excitations and soft-mode transition in the quasi-one-dimensional mixed-spin antiferromagnet Pr{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.54.6437· OSTI ID:383250

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)

Neutron diffraction and inelastic neutron scattering were used to investigate three-dimensional (3D) antiferromagnetic ordering and magnetic excitations in Pr{sub 2}BaNiO{sub 5}, a quasi-1D mixed-spin antiferromagnet. Three distinct features of the magnetic excitation spectrum were observed above the N{acute e}el temperature {ital T}{sub {ital N}}: a strongly 1D gap excitation propagating on the Ni chains, a single-ion crystal-field transition associated with Pr{sup 3+}, and a strongly temperature-dependent mixed Pr-Ni magnetic-exciton band. Ni-chain modes persist in the 3D ordered phase, and the energy gap increases with decreasing {ital T} below {ital T}{sub {ital N}}. The magnetic-exciton band undergoes a complete softening at the antiferromagnetic zone center as {ital T}{sub {ital N}} is approached from above, driving the magnetic phase transition. {copyright} {ital 1996 The American Physical Society.}

• Research Organization: Brookhaven National Laboratory
• DOE Contract Number: AC02-76CH00016
• OSTI ID: 383250
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 9 Vol. 54; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ANTIFERROMAGNETIC MATERIALS
BARIUM OXIDES
COLLECTIVE EXCITATIONS
INELASTIC SCATTERING
MAGNETIC PROPERTIES
NEUTRON DIFFRACTION
NICKEL OXIDES
PHASE TRANSFORMATIONS
PRASEODYMIUM OXIDES
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE 0013-0065 K