Cationic Nonstoichiometry, Crystal Structure, and Magnetic Properties of Eu1-xMn1+xO3.

The features of the formation of crystalline and magnetic subsystems in the Eu1-xMn1+xO3 solid solution depending on the superstoichiometric manganese content were studied by X-ray diffraction analysis (XRD) and magnetometry. XRD showed that an increase in x led to significant decrease in the unit cell volume, which was accounted for by the occurrence of the manganese disproportionation reaction and subsequent redistribution of different valence manganese ions in nonequivalent positions as follows: Eu 1 - x 3 + Mn x 2 + Mn 1 - x 3 + Mn x 4 + O 3 2 - . The degree of orthorhombic and Jahn–Teller distortions decreased with increasing x. The temperatures of magnetic transitions due to manganese ions ordering in the B- and A-sublattices, high-temperature (T1) one and low-temperature (T2) one, respectively, were determined based on the temperature dependences of dM/dT. It was established that an increase in the Mn content reduced the temperature T1. Magnetization measurements performed in Eu0.94Mn1.06O3 in a low applied magnetic field demonstrated magnetization reversal at temperatures below T1. [ABSTRACT FROM AUTHOR]