Magnetic excitations in thulium metal

Journal Article · Tue May 01 04:00:00 EDT 1990 · Journal of Applied Physics; (USA)

DOI:https://doi.org/10.1063/1.344637· OSTI ID:7123486

Fernandez-Baca, J A; Nicklow, R M ^[1]; Rhyne, J J ^[2]

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1. Solid State Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6393 (USA)
2. National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (USA)

We have performed inelastic neutron scattering measurements on a single-crystal specimen of Tm at wave vectors {kappa}=(1, 1,{zeta}) and (0,0,2+{zeta}) ({zeta}=0,...,1). Most of the measurements have been made at {ital T}=5 K, where Tm exhibits a seven-layer ferrimagnetic-antiphase-domain structure (four moments up, parallel to the {ital c} axis, followed by three moments down). At this temperature the excitation spectra consist of three peaks. The two lower energy excitations have been identified as originating from magnetovibrational scattering from the TA phonon, while the higher energy excitation is magnetic and exhibits only a weak dispersion (between 8.3 and 9.6 meV). At {ital T}=50 K, a temperature at which the system exhibits a {ital c}-axis sinusoidally modulated structure, the magnetic mode shows significant softening and broadening. The magnetovibrational scattering vanishes above the Neel temperature ({ital T}{sub {ital N}}=58.5 K) while the magnetic mode persists at least up to {ital T}=70 K. These results suggest that the Hamiltonian in this system is dominated by the crystal-field-anisotropy energy and that the exchange interaction is relatively weak.

• DOE Contract Number: AC05-84OR21400
• OSTI ID: 7123486
• Journal Information: Journal of Applied Physics; (USA), Journal Name: Journal of Applied Physics; (USA) Vol. 67:9; ISSN 0021-8979; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360104* -- Metals & Alloys-- Physical Properties
ANISOTROPY
COHERENT SCATTERING
COLLECTIVE EXCITATIONS
CRYSTAL FIELD
CRYSTALS
DIFFRACTION
ELEMENTS
ENERGY-LEVEL TRANSITIONS
EXCHANGE INTERACTIONS
EXCITATION
INELASTIC SCATTERING
INTERACTIONS
LOW TEMPERATURE
MAGNETIC PROPERTIES
METALS
MONOCRYSTALS
NEUTRON DIFFRACTION
PHONONS
PHYSICAL PROPERTIES
QUASI PARTICLES
RARE EARTHS
SCATTERING
THULIUM
ULTRALOW TEMPERATURE
VERY LOW TEMPERATURE