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对具有不同名义配比及不同烧结条件下形成的Y-Ba-Cu氧化物进行了X射线结构分析。所得实验数据表明:具有较好超导临界参量的样品所含金属Y-Ba-Cu的配比为1∶2∶3,化学组成为YBa_2Cu_3O_(9-x),属畸变的正交钙钛矿型结构。单胞基矢α_(?)=3.821A,6_(?)=3.891A,c_(?)=11.675A,单胞体积V=173.57A~3。当样品中所含金属的比例偏离1∶2∶3时,其X射线衍射谱由多相物质的衍射峰组成。分析还表明:超导性的强弱与衍射峰的强度相关;超导相的形成与否,热处理条件至关重要。
X-ray structure analysis of Y-Ba-Cu oxides with different nominal compositions and different sintering conditions was carried out. The experimental data obtained show that the Y-Ba-Cu ratio is 1: 2: 3, the chemical composition is YBa 2 Cu 3 O 9-x, the orthorhombic perovskite Type structure. The single cell volume α = 3.821A, 6_ (?) = 3.891A, c_ (?) = 11.675A, unit cell volume V = 173.57A ~ 3. When the ratio of the metal contained in the sample deviates from 1: 2: 3, the X-ray diffraction spectrum is composed of the diffraction peak of the heterogeneous substance. The analysis also shows that the strength of the superconductivity is related to the intensity of the diffraction peak. The formation of the superconducting phase and the heat treatment conditions are very important.