Magnetic properties of rare earth rhenium oxides Ln₃ReO₇ (Ln = Y, Er–Lu) with fluorite-related structure

抄録

Ternary rare earth rhenium oxides Ln₃ReO₇ (Ln = Y, Er–Lu) have been prepared. Their X-ray diffraction measurements and the Rietveld analysis show that these compounds have an orthorhombic superstructure of fluorite-type with space group C222₁ (for Ln = Y, Er, Tm) or a defect-fluorite structure Fm3m (for Ln = Yb, Lu). The zero-field-cooling and field-cooling magnetic susceptibility for Y₃ReO₇ diverse when the temperature is decreased through 10 K. At the same temperature, specific heat anomaly is also observed. The results of the specific heat measurements for Tm₃ReO₇ and Yb₃ReO₇ indicate the existence of magnetic anomaly below 7 and 2.2 K, respectively. On the other hand, Er₃ReO₇ and Lu₃ReO₇ are paramagnetic down to 1.8 K.