Effect of magnetic dilution on magnetic ordering in Ni<i>p</i>Mg1−<i>p</i>O

Abstract

About 20 powder samples of the fcc diluted system NipMg1−pO (0.06&amp;lt;p&amp;lt;1) were prepared and their structural and magnetic properties were measured. The lattice constant a(p) fits the variation a(p)=4.2115−0.0340 p. From the magnetic susceptibility versus temperature data, the Néel temperatures TN are determined. The variaton of t= TN(p)/TN(1) versus p is found to be similar to that in CopMg1−pO for p≳0.32 and it is found to fit the predicted values for a simple cubic Heisenberg antiferromagnet. A theoretical justification for this observation is advanced.