Low Temperature Physics: 40, 629 (2014); https://doi.org/10.1063/1.4890992
AFM resonance study into magnetic structure of Nd0.75Dy0.25Fe3(BO3)4
M.I. Kobets, K.G. Dergachev, E.N. Khatsko, S.L. Gnatchenko
B. Verkin Institute for Low Temperature Physics and Engineering of the National Academy of Sciences of Ukraine 47 Lenin Ave., Kharkov 61103, Ukraine
L.N. Bezmaternykh, and I.A. Gudim
L.V. Kirenskiy Institute of Physics, Siberian Branch of the Russian Academy of Sciences Krasnoyarsk 660036, Russia
Received Jule 25, 2013, revised August 8, 2013
The influence of substitution of Dy3+ ions for Nd3+ ones on the magnetic properties of the Nd0.75Dy0.25Fe3(BO3)4 single crystal was investigated. The resonance studies were carried out in a wide range of frequencies 40–145 GHz and external magnetic fields 0–75 kOe. We have detected a magnetic spin-reorientation easy axis–easy plane phase transition magnetic field Hcr = 15.85 kOe and studied the frequency-field dependence of the AFMR spectrum before and after the phase transition, at T = 4.2 K. The resonance spectra observed along the direction of H||c are antiferromagnetic resonance modes of iron at a T = 4.2 K. Their frequency-field dependences correspond to the easy-axis (H < 15 kOe) and easy-plane (H > 16 kOe) magnetic structures with energy gaps of magnon excitation of 77.2 and 100.3 GHz, re-spectively. The effective magnetic anisotropy, that forms these energy gaps is equal to 0.7 and 1.2 kOe. The doping Dy3+ ions of the Nd0.75Dy0.25Fe3(BO3)4 single crystal produce to a static internal field, which shifts the resonance field of the ESR absorption line and changes the value of g factor of the Fe3+ ions due to polarization in the paramagnetic region.
PACS: 75.50.Ee Antiferromagnetics;
Key words: antiferromagnetic, resonance, multiferroics, electron paramagnetic resonance.
Published online: May 21, 2014