Effects of the Tb-Ion Concentration in Multiferroic Tb_xY_(1-x)Mn_(1.99)~(57)Fe_(0.01)O_5(x =0.0, 1.0) Materials

摘要

Multiferroic (x =0.0, 1.0) was synthesized by using a sol-gel method.The lattice constants ofTb_xY_(1-x)Mn_(1.99)~(57)Pe_(0.1)O_5with Tb substitution ofx =0.0 andx 1.0were determined to be a_0 = 7.275A,b_0 = 8.487A, c_0 =5.674Aand a_7.334A, b_8.523A, c_0 =5.679A,respectively. The magnetic moment of YMn_(1.99)Fe_(0.01)O_5decreased sharply withtemperature down to a temperature of 25 K due to the canted magnetic moment. However, alarge increase in the magnetic moment was observed in TbMn_(1.99)Fe_(0.01)O_5. The Mossbauer spectraof Tb_5 (x = 0.0, 1.0) exhibited two-sextet patterns at 4.2 K. There was anoticeable difference in magnetic hyperfine fields at the tetrahedral site (Y.H_hf~A, , TbH_(hf)~A)We also observed similar behaviours in the electric quadrupole splitting values at pyramidal site (Δ~YE_Q~AΔ~(Tb)E_Q~A).Furthermore, the electric quadrupole splitting ofTb_0.0,1.0) showed discontinuous jump below 30 K. These suggest that the multiferroic properties ofTb_xY_(1-x)Mn_(1.99)~(are greatly affected by the magnetic ordering.