Role of antiferromagnetic interlayer coupling on magnetic properties of YBa2Cu3O6+x.

In this paper we have studied the role of interlayer coupling on the Neel temperature of YBa 2 Cu 3 O 6+x . We have used the expression for the Neel temperature derived from the three-dimensional anisotropic Heisenberg model in the random-phase approximation. With the help of numerical calculations we have obtained an analytical expression for the Neel temperature as T N =J ∥/[0.1616In(J ∥/J ⊥)+0.5055]/k B . This expression shows that T N →0 as J ⊥→0