MAGNETIC-INTERACTIONS IN DYALO3 AND TBALO3

The behaviour of the magnetic specific heats of the antiferromagnets D yAlO3 and TbAlO3 have been analysed near their respective Neel tempera tures and the energy and entropy distributions determined. Comparison with theoretical predictions show that the parameters do not agree wit h the values expected for a 3D s.c. Ising antiferromagnet with S = 1/2 . The results are discussed in terms of conflicting literature stateme nts about the relative contributions of dipolar and exchange interacti ons to the ordering. (C) 1998 Elsevier Science B.V. All rights reserve d.