Magnetic susceptibility and order parameter of the spin-glass-like phase of the double-exchange model.
The magnetic susceptibility and Edwards-Anderson order parameter q of the spin-glass-like (SGL) phase of the double-exchange model are evaluated in the weak-coupling or RKKY limit. Dynamical mean-field theory is used to show that q = M(T/T(SGL))2, where M is the classical Brillouin function and T(SGL) is the SGL transition temperature. The correlation length of the SGL phase is determined by a correlation parameter Q that maximizes T(SGL) and minimizes the free energy. The magnetic susceptibility has a cusp at T(SGL) and reaches a nonzero value as T --> 0.
Fishman
Randy S
RS
Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6032, USA.