High-temperature expansion for the random mixture of the ferromagnetic and antiferromagnetic exchange interactions

Abstract

The critical temperature Tc of the random mixture of the ferromagnetic and antiferromagnetic exchange interactions JA and JB on both the two-dimensional square lattice and the simple cubic lattice are discussed by using Pade approximations of the high-temperature expansion of the susceptibility. It is suggested that the critical temperature Tc (between the paramagnetic and the ferromagnetic phases) which decreases with pA, where pA is the concentration of JA, disappears at a certain concentration pAc1 before it reaches the absolute zero temperature. This fact supports the theory of the glass-like phase and there are triple points where the paramagnetic phase, the ferromagnetic (antiferromagnetic) phase and the glass-like phase join together.