Temperature dependence of exchange stiffness in garnet bubble films

The temperature dependence of the exchange stiffness is taken into account to predict the room-temperature exchange stiffness of substituted YIG films for bubble applications. A simple theory leads to the linear relation of A(T,T N) = AYIG(T)[TN-T)/(TN, YIG -T)] where AYIG(T) is the exchange stiffness of YIG at the ambient temperature T and A(T,TN) is the exchange constant at T of a film with Neél temperature TN. This relation is in reasonable agreement with the recent spin-wave resonance data of Henry and Heinz. © 1974 American Institute of Physics.