Effect of Al-doped YCrO₃ on structural, electronic and magnetic properties

Structural, dielectric and magnetic properties were investigated in the YCr_1−xAl_xO₃ with 0 < x < 0.5 compositions. XRD and XPS studies show that the partial substitution of the Al³⁺ ion decreases the cell volume of the orthorhombic structure without changes in the oxidation state of the Cr³⁺ ions. We discuss two mechanisms that could have a significant influence on the magnetic properties. The first is related to local deformation occurring for x < 0.1 of Al content and the second is related to change of the electronic structure. The local deformation is controlled by the inclination of the octahedrons and the octahedral distortion having a strong effect on the T_N and the coercive field at low Al concentrations. On the other hand, the decreasing of the magnetization values (M_r and H_c) is ascribed to changes in the electronic structure, which is confirmed by a decreasing of the contribution of Cr 3d states at Fermi level due to increasing Al³⁺ content. Thus, we analyzed and discussed that both mechanisms influence the electronic properties of the YCr_1−xAl_xO₃ solid solution.