We studied the absorption spectra of single crystals of rare-earth borates RFe3 (BO3)4, R = Y, Er, Tb, Gd with erbium (1 %) introduced as a probe. We determined the magnetic ordering temperatures TN = 39 ± 1, 38 ± 0.5, 41 ± 1, and 37 ± 1 K of iron borates of Er, Y, Tb, and Gd, respectively, and the temperatures TR = 7.5 ± 0.5 K of the first-order spin-reorientation phase transition in GdFe3 (BO3)4: Er3+ (1 %) using the temperature dependences of splittings of Er3+-ion spectral lines. Comparing the values of the splittings of the ground states of Er3+ ions in the compounds RFe3 (BO3)4 (R=Y, Er, Nb) and GdFe3 (BO3)4, whose magnetic structure is well known, we suggest the following orientation patterns of Fe magnetic moments in the magnetically ordered state: the easy-plane structure for YFe3(BO3)4 and ErFe3(BO3)4 and the easy-axis structure for TbFe3(BO3)4. The effect of one-ion anisotropy of the R3+ ion on identification of a particular magnetic structure in RFe3(BO3)4 is discussed.
|Original language||English (US)|
|Number of pages||9|
|Journal||Bulletin of the Russian Academy of Sciences: Physics|
|State||Published - Dec 1 2006|
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)