Structural studies of Ca and transition metal co-doped system (La1−x Ca x O)Cu1−x M x S (, Co, Ni, Zn)

Abstract: We have precisely investigated the crystal structure of various doped samples of (La1−x Ca x O)Cu1−x M x S (, Co, Ni, Zn) in order to understand changes of the electrical properties from a view point of the crystal structure. The distance between LaO and CuS layers along c-axis, increases with increasing electrical resistivity of (La1−x Ca x O)Cu1−x Ni x S and it approaches a value of insulating samples, (La1−x Ca x O)Cu1−x M x S (, Co, Zn). The changes of the electrical properties is considered to be due to the charge transfer between LaO and CuS layer which is caused by the change of . [Copyright &y& Elsevier]