Absorption and magneto-optical properties of the /sup 3/A/sub 2g/. -->. /sup 1/T/sub 2g//sup a/ transition in CsNiF/sub 3/. II. Pure-exciton and hot-magnon bands in a one-dimensional ferromagnet
Absorption spectra associated with the lowest-energy region of the spin-forbidden transition /sup 3/A/sub 2g/..-->.. /sup 1/T/sub 2g//sup a/ in CsNiF/sub 3/ are investigated in the one-dimensional ferromagnetic phase in magnetic fields up to 4.5 T. Pure-exciton bands are found to have a linear blue shift with a field applied in the easy plane, whereas the hot-magnon band shifts slightly to lower energies. When the field is increased the intensity of the exciton bands increases and the absorption due to the hot-magnon band decreases. An anomalous behavior of the band intensities and the half-widths is observed in fields below 1 T. The structure of the exciton spectra and their field dependence are discussed by using an energy-level scheme obtained by a single-ion approximation. The properties of the hot-magnon sideband are explained by the exciton creation accompanied by the annihilation of a thermally excited magnon at the Brillouin-zone edge. The anomalies of the exciton and the hot-magnon bands observed in low fields may be understood by the reduction of spin fluctuations in a magnetic field applied in the easy plane of magnetization.
- Research Organization:
- Physics Department, Kyoto Sangyo University, Kyoto 603, Japan
- OSTI ID:
- 5651707
- Journal Information:
- Phys. Rev. B: Condens. Matter; (United States), Vol. 32:3
- Country of Publication:
- United States
- Language:
- English
Similar Records
Pure exciton- and magnon-assisted optical transitionsin the one-dimensional antiferromagnet CsMnCl/sub 3/x2H/sub 2/O (CMC)
Rotationally resolved pulsed field ionization photoelectron bands of O[sub 2][sup +](X [sup 2][Pi][sub 1/2,3/2g],v[sup +]=0[endash]38) in the energy range of 12. 05[endash]18. 15 eV
Related Subjects
CESIUM FLUORIDES
MAGNETO-OPTICAL EFFECTS
MAGNONS
NICKEL FLUORIDES
ABSORPTION
ENERGY LEVELS
EXCITONS
FERROMAGNETIC MATERIALS
FORBIDDEN TRANSITIONS
MAGNETIC FIELDS
ALKALI METAL COMPOUNDS
CESIUM COMPOUNDS
ENERGY-LEVEL TRANSITIONS
FLUORIDES
FLUORINE COMPOUNDS
HALIDES
HALOGEN COMPOUNDS
MAGNETIC MATERIALS
MATERIALS
NICKEL COMPOUNDS
QUASI PARTICLES
TRANSITION ELEMENT COMPOUNDS
360603* - Materials- Properties