THERMAL-EXPANSION MEASUREMENTS USING NEUTRON-DIFFRACTION OF (BI, PB)2CA2SR2CU3OX

The high temperature superconductor (Bi, Pb)2Ca2Sr2Cu3Ox, Bi-(2223), will likely be used in the form of metal sheathed tapes of the oxide, in which the crystals of the material are aligned relative to the surface of the tape. In order to properly engineer these composite structures, a detailed knowledge of the physical properties of the components is required, one parameter being the anisotropic thermal expansion of the superconducting oxide. The temperature dependence of the lattice parameters was determined using neutron powder diffraction and the results presented in terms of the thermal expansion of the material in these directions.