Abstract

We prepared solid solutions of antiferromagnetic LuCrO₄ and ferromagnetic YCrO₄, i.e., Lu_1−xY_xCrO₄ (x = 0–1.0 at 0.125 intervals). Their precise crystal structures were determined from the X-ray diffraction measurements. All the solid solutions have a zircon-type structure with space group I4₁/amd (No. 141). Their magnetic susceptibility measurements have been performed in the temperature range between 1.8 K and 300 K. The solid solutions for x = 0–0.375 show an antiferromagnetic transition and those for x = 0.5–1.0 show a ferromagnetic transition at low temperatures. It was found that the magnetic transition temperatures for the solid solutions were lower than those for pure LuCrO₄ (9.1 K) and YCrO₄ (9.2 K), and the Curie temperature for Lu_0.5Y_0.5CrO₄ is the lowest (5.2 K). The magnetization curves indicate the occurrence of metamagnetism for Lu_0.75Y_0.25CrO₄ and Lu_0.625Y_0.375CrO₄. Specific heat measurements have been performed for Lu_1−xY_xCrO₄ (x = 0, 0.375, 0.5, 1) in the temperature range between 1.8 K and 300 K. λ-Type anomalies have been found at their magnetic transition temperatures. Magnetic entropy change due to magnetic exchange interactions has been evaluated from the specific data.