Ferrimagnetic order in the mixed garnet (Y_1−xGd_x)₃Fe₅O₁₂

Abstract

Ferrimagnetic order in the mixed rare-earth iron garnet (Y_{1 −  x} Gd _x )₃Fe₅O₁₂ system has been reinvestigated to cover the temperature range 5.0 to 700 K. The magnetization versus temperature exhibits a systematic variation with changing concentration x. The ferric-ion exchange coupling is strong enough to determine the Curie temperature ≈559 K for all the values x. The compensation temperature at which the magnetization crosses zero (shows the minimum) demonstrates the applicability of the three-sublattice model. The magnetic moment at 5.0 K indicates reasonable agreement with the relation n _B = |21x − 5.0|μ_B for the (Y_{1 −  x} Gd _x )₃Fe₅O₁₂ system. The compensation temperature decreases with decreasing x from 1.0 and reaches zero near x = 0.24. An enlargement of coercive force in the hysteresis loop for the low-field M-H curve is clearly seen in near the compensation temperature, indicating that a single domain is formed and the rotation of this single domain occurs without building up a multidomain structure.