Impact of Cu Doping on the Structure and Electronic Properties of LaCr_1–<i>y</i>Cu_<i>y</i>O₃

Oxides of the type LaCr_1–<i>y</i>Cu_<i>y</i>O₃ have been prepared using solid-state methods and their crystal structures refined using synchrotron X-ray powder diffraction. The solubility limit of Cu was found to be around <i>y</i> = 0.2, and such oxides are orthorhombic in space group <i>Pbnm</i>. X-ray absorption spectroscopy measurements at the Cr and Cu L-edges demonstrated that the Cr remains trivalent upon Cu doping, with the Cu being present as Cu­(III). The oxides are found to be antiferromagnets, and the Néel temperature, <i>T</i>_N, decreases as the Cu content is increased. The crystal and magnetic structures of one example La­(Cr_0.85Cu_0.15)­O₃ have been investigated between 3 and 350 K by neutron powder diffraction. The samples are semiconductors