Structural and magnetic properties of high-pressure/high-temperature synthesized (Sr1–xRx)CoO3 (R=Y and Ho) perovskites

Polycrystalline perovskite cobalt oxides Sr1–xRxCoO3 (R  =Y and Ho; 0⩽x⩽10⩽x⩽1) were prepared by high-pressure/high-temperature technique. X-ray powder patterns of the Y-system indicated cubic perovskite form for 0⩽x⩽0.50⩽x⩽0.5, and orthorhombic perovskite form for x=0.8x=0.8 and 1.0, while coexisting of the two phases for x=0.6x=0.6. The cubic perovskite samples had metallic electric resistivities while the orthorhombic ones with semiconducting or insulating nature. The parent compound SrCoO3 showed a ferromagnetic transition at 266 K. With the Y substitution, the transition temperature increased slightly to ∼275 K at x=0.1x=0.1, then decreased rapidly to ∼60 K for x=0.6x=0.6. The YCoO3 (x=1x=1) sample showed non-magnetic behavior. The Ho-substituted system showed quite similar structural, transport and magnetic properties to those of the Y-system.

Temperature dependence of M/H for the Sr1–xYxCoO3 system measured at an applied field of 1 kOe by the field-cooling mode.Figure optionsDownload as PowerPoint slide