Journal of Statistical Physics, Vol. 57, Nos. 1/2, 1989. p. 411-414.
Monte Carlo simulations are performed for pure and site-diluted Ising antiferromagnets on a simple cubic lattice with up to 40^3 sites and impurity concentration x = 0, 0.2, and 0.5. For x = 0.5 a cusp emerges for the temperature dependence of the uniform susceptibility at the critical temperature which is contrasted with the smooth behavior for a pure antiferromagnet, in agreement with the theoretical prediction of Fishman and Aharony.