Antiferromagnetic transition in CuRh2O4

Heat-capacity and magnetic susceptibility measurements were carried out on the normal spinel-type compound CuRh2O4. A sharp heat capacity anomaly asso ciated with an antiferromagnetic transition was first observed. The Neel te mperature T-N was 21.9 K which indicates the inflection point of the magnet ic susceptibility chi, being lower than the peak temperature of 24 K in chi . The effective magnetic moment observed was 1.88 mu(B) per molecule. which is close to the spin-only moment for Cu2+ ion. The value of the magnetic e ntropy change was 2.72 J K-1 mol(-1) which is much less than that expected for R ln(2S + 1). S = 1/2. These results for CuRh2O4 based on the ionic pic ture have an important relevance to Cu-ternary chalcogenides with a similar structure. (C) 1999 Elsevier Science Ltd. All rights reserved.