Кл.слова (ненормированные):
Magnetic resonance -- Rare-earth iron borates -- Terahertz spectroscopy -- Antiferromagnetics -- Coupled mode -- Exchange coupled -- Frequency ranges -- G factors -- Iron borate -- Magnetic excitations -- Multiferroics -- Resonance mode -- Strong interaction -- Transmission spectrums -- Antiferromagnetism -- Electron transitions -- Gadolinium -- Ions -- Magnetic materials -- Magnetic permeability -- Magnetic resonance -- Terahertz spectroscopy -- Neodymium
Аннотация: Various resonance modes were observed in the transmission spectra of rare-earth iron borates RFe 3(BO 3) 4 (R = Nd 3+, Sm 3+, Gd 3+) at the frequency range 100-600 GHz, which were attributed to collective magnetic excitations in the exchange coupled Fe- and R-subsystems, i.e. antiferromagnetic (Fe) resonance and electron transitions in the R-ions. Strong interaction of the Fe and R oscillations was revealed and theoretically analyzed taking into account feature of the R-ion ground state. Intensities of the coupled modes (contributions to magnetic permeability) strongly depend on a difference of Fe and R ions g-factors that allows defining the sign of the latter. In particular, an appreciable intensity of exchange (Nd) modes in NdFe 3(BO 3) 4 is caused by g Nd?,|| < 0 whereas in GdFe 3(BO 3) 4 with gGd ? gFe ? 2 the exchange (Gd) modes were hided due to compensation of Fe and Gd contributions. In SmFe 3(BO 3) 4, despite a negligible Sm g-factor, the Sm modes were clear observed due to their excitation via coupling with the Fe-subsystem. В© (2012) Trans Tech Publications.
Scopus
Доп.точки доступа:
Kuzmenko, A. M.; Кузьменко А.М.; Mukhin, A. A.; Ivanov, V.Yu.; Bezmaternykh, L. N.; Безматерных, Леонард Николаевич; Moscow International Symposium on Magnetism(5 ; 2011 ; Aug. ; 21-25 ; Moscow)