Observation of a new type of magnetic excitations in NdFe3(BO3)4 ferroborate
M. Kobets1, K. Dergachev1, A. Kovalev1,2, S. Gnatchenko1, and E. Khatsko1
1B. Verkin Institute for Low Temperature Physics and Engineering of the National Academy of Sciences of Ukraine 47 Lenin Ave., Kharkov 61103, Ukraine
2V.N. Karazin Kharkov National University, Kharkov 61077, Ukraine pos Анотація:
Received Jule 19, 2013, reseived August 21, 2013
The AFMR spectra of the NdFe3(BO3)4 crystal of an incommensurate state are measured in ranges of frequencies 15–32.2 GHz, temperatures 2.17–10 K and fields H < Hsf. It is found that the incommensurability of the magnetic ordering in these ranges of parameters leads to an essential change of the resonant properties of the system. The frequency of the “usual” resonance remains finite up to the spin-flop transition field Hsf, and a new branch of excitations with unusual hysteresis properties arises. The dependences of resonant frequency on field and temperature are found in the above ranges of these parameters.