X-ray Powder Diffraction Reference Patterns for Bi1-xPbxOCuSe
Winnie K. Wong-Ng, Yonggao Yan, James A. Kaduk, Xinfeng Tang
The structures and powder X-ray reference diffraction patterns of the natural superlattice series Bi1-xPbxOCuSe (x=0, 0.02, 0.04, 0.06, 0.08 and 0.1) have been investigated. As the ionic radius of Pb2+ is greater than that of Bi3+, the unit cell volume of Bi1-xPbxOCuSe increases progressively from x=0 to x=0.1, namely, from 137.868(5) Å3 to 139.172(11) Å3, as expected. The structure of Bi1-xPbxOCuSe is built from [Bi2(1-x)Pb2xO2]2(1-x)+ layers normal to the c-axis alternating with [Cu2Se2]2(1-x]- fluorite-like layers. Pb substitution in the Bi site of Bi1-xPbxOCuSe leads to the weakening of the bonding between the [Bi2(1-x)Pb2xO2]2(1-x)+ and the [Cu2Se2]2(1-x]- layers. Powder patterns of Bi1-xPbxOCuSe were submitted to be included in the Powder Diffraction File (PDF).