MAGNETIC-ANISOTROPY AND MAGNETIC PHASE-TRANSITIONS IN RFE(10)MO(2) (R=PR,ND,SM,DY,HO,ER,TM)

RFe(10)Mo(2) (R=Pr, Sm, Nd, Dy, Ho, Er, Tm) intermetallics were invest igated by studying the temperature or field-induced spin-reorientation transitions (SRT's). The temperature dependence of the magnetic aniso tropy field was determined by means of the singular point-detection te chnique for the polycrystalline samples of YFe10Mo2, NdFe10Mo2, DyFe10 Mo2, and ErFe10Mo2. Main emphasis was given to the theoretical analysi s of the magnetic anisotropy constants and the magnetic phase transiti ons. The temperature dependences of the rare-earth anisotropy constant s were calculated using the single-ion model within linear theory. The applicability of the linear theory of the R anisotropy is discussed. It is shown that the accuracy of this theory increases considerably wi th increasing temperature. Fitting the experimental data, a set of the crystal field and exchange field parameters for the rare-earth R(3+) ions was deduced. The observed SRT's and first-order magnetization pro cesses (FOMP's) were explained and classified. FOMP-like transitions i n PrFe10Mo2, HoFe10Mo2, and ErFe10Mo2 were identified. The temperature dependence of the FOMP fields was calculated for HoFe(10)MO(2) and Er Fe10Mo2. The physical origin of a low-temperature anomaly in the magne tization process is discussed for SmFe10Mo2. The spin-reorientation tr ansitions:in ErFe10Mo2 and TmFe10Mo2 are determined to be of first ord er with a discontinuous jump of the magnetization. The SRT's detected in NdFe10Mo2 and DyFe10Mo2 are of second order. The calculated tempera ture dependences of the anisotropy fields for DyFe10Mo2 and NdFe10Mo2 are in good agreement with the experimental data over a wide temperatu re range. FOMP's are predicted at low temperatures for NdFe10Mo2, DyFe 10Mo2, and TmFe10Mo2.