Structural Studies of Layered Magnetic Semiconductor (La1−xCaxO)Cu1−xNixS

Crystal structure of layered magnetic semiconductors (La1−xCaxO)Cu1−xNixS which show ferromagnetism even at room temperature has been investigated precisely using synchrotron x‐rays to understand their physical properties from a view point of the crystal structure and check magnetic impurities. No magnetic impurities were found and this means that these ferromagnetic characters are intrinsic properties. Precise structural analysis indicate that the interlayer distance between S‐Cu2‐S and La‐O2‐La layers decreases with increasing concentration x. The increase of x leads to reduce the electrical resistivity. From these results, the interaction between LaO and CuS layers is therefore important in controlling the physical properties of these compounds.