Re-entrant ferromagnetism in 2D and 3D Ising model with random nearest-neighbour interactions

摘要

We present the study of phase diagrams in spin-1/2 Ising model for honeycomb, square, triangular and simple-cubic lattices using the two-spin cluster approximation. We consider nearest-neighbour ferromagnetic exchange interactions J with concentration p and exchange interactions /spl alpha/J (|/spl alpha/|>1) with concentration (1-p). The phase diagrams in /spl alpha/-t/sub c//sup -1/ plane show re-entrant behavior in certain ranges of concentration p.