【摘要】 以分析纯的BaCO3、WO3以及W粉为原料,通过混合微波方法合成了钡物青铜BaxWO3(0.14≤x≤0.25).样品的晶体结构为正交和四方两相共存,随着x的增加正交相的衍射峰逐渐减弱,而四方相的衍射峰呈现出增强的趋势.当x从0.14增加到0.25时,电阻率ρ下降了约两个数量级,且在x=0.2附近发生了从半导体到金属的转变.交流磁化率测量显示Ba0.21WO3在Tc=2.4K时发生了超导转变.更多还原

【Abstract】 The barium tungsten bronzes BaxWO3(0.14≤x≤0.25) have been prepared from BaCO3,WO3 and W powders using hybrid microwave method.The two phases,orthorhombic and tetragonal,coexist in all samples,and the intensity of peaks for the former is gradually weakened and that for the latter is strengthened with the increase of x.The resistivity for samples drops by about 2 orders of magnitude as x changing from 0.14 to 0.25,and the semiconductor-metal transition occurs around x=0.20.For sample Ba0.21WO3,the superconducting transition appears at Tc=2.4K from the ac susceptibility measurements.更多还原