Quasioptical study of antiferromagnetic resonance in YFeO3 at submillimeter wavelength under high pulsed magnetic fields.
Transmission spectra, T(H), of linearly polarized electromagnetic waves through YFeO(3), weak ferromagnet, measured at frequencies nu=96-1000 GHz in long-pulsed magnetic fields (H||k||c-axis, Faraday geometry) exhibit strong rotation of the polarization plane near the quasiferromagnetic AFMR as well as low frequency impurity modes. New ascending impurity branch including five lines was observed at high magnetic field (10-30 T) at 96 GHz and 140 GHz in addition to the known low-field descending impurity branch. Behavior of all the impurity modes assigned to transitions in (6)S(5/2) multiplet of Fe(3+) "impurity" ions in c-sites was described self-consistently by one spin-Hamiltonian. A theoretical calculation of dynamical magnetic susceptibility at AFMR and impurity modes and further simulation of transmission spectra made it possible to describe the main features of the observed spectra T(H). It was found that the T(H) behavior is determined at resonances not only by non-diagonal components of the magnetic susceptibility but also by the anisotropy of the dielectric permittivity (epsilon(xx)(') not equal epsilon(yy)(')), i.e. birefringence.
Mukhin
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AA
A.M. Prokhorov General Physics Institute RAS, Submillimeter Spectroscopy, 38, Vavilov Street, Moscow 119991, Russian Federation. mukhin@ran.gpi.ru
Lobanov
A N
AN
Goiran
M
M
Leotin
J
J
Volkov
A A
AA
D004574:Electromagnetic Fields; D005290:Ferric Compounds / Q000737:chemistry*; D008280:Magnetics; D008872:Microwaves; D012542:Scattering, Radiation; D012815:Signal Processing, Computer-Assisted; D015019:Yttrium / Q000737:chemistry*
D005290:Ferric Compounds; C000499:ferric oxide; D015019:Yttrium