Ferrimagnetism and possible double perovskite structure in half Cr-doped YMn0.5Cr0.5O3

Half Cr-doped YMn0.5Cr0.5O3 polycrystalline has been synthesized by means of a standard solid-state reaction method. Powder X-ray diffraction gives evidence that the sample is a single phase of orthorhombic (Pbnm) or monoclinic (P2(1)/c) structure as observed for other doped manganites, rather than the hexagonal structure as YMnO3. Upon cooling, the magnetic susceptibility increases sharply at T-C similar to 75 K, indicating a magnetic ordering occurs. The detailed analysis on the paramagnetic behavior at higher temperatures reveals that the low-temperature order is a ferrimagnetic state. The electrical transport properties show an insulator behavior dominated by the adiabatic small polaron hopping mechanism with high thermal activation energy. The results indicate that the ferromagnetic double exchange (DE) interaction is unreasonable in Cr-doped manganites. (C) 2013 Elsevier B.V. All rights reserved.