New rare earth vanadates YSr_(Q-x)Ca_xV_3O_(9-y)(x=0.0, 0.67, 1.0, 1.33 and 2.0) have been synthesized by a new simple method. X-ray powder diffraction results show that they are mono-phase. They belong to orthorhombi...New rare earth vanadates YSr_(Q-x)Ca_xV_3O_(9-y)(x=0.0, 0.67, 1.0, 1.33 and 2.0) have been synthesized by a new simple method. X-ray powder diffraction results show that they are mono-phase. They belong to orthorhombic structure and their lattice constants are calculated. The results of weight gains in TG curves show that the lower valent vanadium is oxidized to higher valent state at higher temperature. The oxygen contents of new compounds are calculated from the weight gains. Both V^(3+) and V^(4+) coexist in YSr_(2-x)Ca_xV_3O_(9-y). These compounds exhibit low electric resistivity at room temperature.展开更多
文摘New rare earth vanadates YSr_(Q-x)Ca_xV_3O_(9-y)(x=0.0, 0.67, 1.0, 1.33 and 2.0) have been synthesized by a new simple method. X-ray powder diffraction results show that they are mono-phase. They belong to orthorhombic structure and their lattice constants are calculated. The results of weight gains in TG curves show that the lower valent vanadium is oxidized to higher valent state at higher temperature. The oxygen contents of new compounds are calculated from the weight gains. Both V^(3+) and V^(4+) coexist in YSr_(2-x)Ca_xV_3O_(9-y). These compounds exhibit low electric resistivity at room temperature.
