Wide Composition Range of T^*-Phase Compound Pr_1.6-xY_xSr_0.4CuO_y (0≤x≤0.6)

Measurements of X-ray diffraction, magnetic susceptibility and electric resistivity have been carried out for the Pr1.6-xYxSr0.4CyOy system. The T* phase is obtained in the composition range 0 less-than-or-equal-to x less-than-or-equal-to 0.6. T* phases are also obtained in Nd1.6-xLnxSr0.4CuOy systems (Ln; Y, Ho, Er, Tm, Yb and Lu), but in a narrow x range such as that of other known T*-phase compounds. The electric resistivity of the Pr system shows systematic rises accompanied by an increase in Pr concentration. This behavior is similar to that of (Pr-Ln)Ba2Cu3O7 in a higher Pr concentration region. Both the wide composition range and the rise of resistivity may be due to the same factor.