X-RAY POWDER DIFFRACTION STUDY OF MIXED BISMUTH OXIDE FERROELECTRICS WITH LAYER TYPE STRUCTURE PbBi4Ti4O15 AND SrBi4Ti4O15
含铋层状结构铁电体PbBi4Ti4O15和SrBi4Ti4O15的X射线衍射数据的测定

The X-ray powder diffraction patterns of mixed bismuth oxide ferroelectrics with layer type structure PbBi4Ti4O15 and SrBi4Ti4O15 were obtained with a counter diffractometer and a Guinier focusing camera using Cu Ka radiation. The detail indexed powder diffraction data of 88 and 76 diffraction lines of which d value are larger than 1.13? were given. The crystals belong to the orthorhombic system with a space group of Bb21m(C2v12). The lattice parameters and density calculated from X-ray measurements are:PbBi4Ti4O15: a = 5.431?, a = 5.459?,c = 41.36?;Z = 4;DX = 7.986g/cm3. SrBi4Ti4O15;a = 5.428?, 6 = 5.438?, c = 40.94?;Z = 4; Dx = 7.447g/cm3.