Crystal structure of Bi4Ti3O12
Crystal structure of Bi4Ti3O12
复制标题
DOI：
10.1080/00150197108237680
复制
发表时间：
1972-02
期刊：
影响因子：
0.8
通讯作者：
J. Dorrian;R. Newnham;D. K. Smith;M. Kay
中科院分区：
文献类型：
--
作者：
J. Dorrian;R. Newnham;D. K. Smith;M. Kay
用X射线衍射和中子衍射测定了Bi_4 Ti_3 O_（12）的晶体结构。物理性质表明单斜对称，但衍射数据与极性正交结构一致，空间群B2 c B，a = 5.448（2），B = 5.411（2），c = 32，83（1）A，Z = 4。使用自动衍射仪测量2500个X射线反射的积分强度，并且从粉末图案获得28个中子峰的强度。最终的R-因素之间的细化结构和X射线和中子数据分别为0.07和0.09。钛是极化沿着a的主要贡献者，从八面体中心平均偏移0.32 A。根据离子上的点电荷计算的自发极化为28 μC/cm 2，沿沿着a，略小于观测值50 ± 5 μC/cm 2。铋键非常不对称，导致八面体绕a和c旋转。一个模型，涉及相关的重定向的长…
The crystal structure of Bi4Ti3O12 has been determined from x-ray and neutron diffraction patterns. Physical properties indicate monoclinic symmetry, but the diffraction data are consistent with a polar orthorhombic structure, space group B2cb, with a = 5.448(2), b = 5.411(2), c = 32,83(1) A, and Z = 4. Integrated intensities of 2500 x-ray reflections were measured using an automated diffractometer, and the intensities of 28 neutron peaks were obtained from powder patterns. Final R-factors between the refined structure and the x-ray and neutron data were 0.07 and 0.09, respectively. Titanium is the principal contributor to polarization along a, shifting an average of 0.32 A from the octahedron centers. The spontaneous polarization, calculated on the basis of point charges on the ions, is 28 μC/cm2 along a, somewhat smaller than the observed value of 50 ± 5 μC/cm2. The bismuth bonding is very asymmetric, causing rotations of the octahedra about a and c. A model involving the correlated reorientation of lon...