Antiferromagnetic resonance in cubic RbMnF₃

Abstract

Antiferromagnetic resonance has been observed in cubic RbMnF3, and the results are in excellent agreement with a theoretical treatment of the resonance conditions. Because a more detailed publication has recently appeared,1 we present in this abstract a brief background and comments on the observed temperature dependence. Cubic RbMnF3 is characterized by a strong exchange interaction (TN≃54.5°K) 2 and low anisotropy. The anisotropy energy has the form E A = K(4+4+4), where K is positive. When the sublattice magnetization is close to the preferred {111} direction, the anisotropy may be represented by an effective field of 5.0 Oe at 4.2°K. The exchange field is found to be 710 kOe. The exchange and anisotropy fields may be determined separately because the nuclear anisotropy field, HN, may be calculated and the exchange field obtained from 2H EH N = 2HE× (9.43T). We are presently investigating the temperature dependence of the resonance field in the helium range. Within the experimental uncertainty of 2, we find no change in H EHA from 1.4°to 4.2°K. Work is in progress to extend the temperature range and to increase the experimental accuracy. © 1963 The American Institute of Physics.