Abstract
Using Tyablikov's decoupling approximation, we calculate the initial suppression rate of the Néel temperature, R IS = - lim x → 0 T N - 1 d T N / d x , in a quasi two-dimensional diluted Heisenberg antiferromagnet with nonmagnetic impurities of concentration x. In order to explain an experimental fact that R IS ( Zn ) = 3.4 of the Zn-substitution is different from R IS ( Mg ) = 3.0 of the Mg-substitution, we propose a model in which impurity substitution reduces the intra-plane exchange couplings surrounding impurities, as well as dilution of spin systems. The decrease of 12% in exchange coupling constants by Zn substitution and decrease of 6% by Mg substitution explain those two experimental results, when an appropriate value of the inter-plane coupling is used.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
