Magnetic properties and local microstructures in Zn-doped YMnO3

The hole doping effect on the magnetic properties of multiferroic YMn1−xZnxO3 was studied through investigating the local microstructures. Polycrystalline YMn1−xZnxO3 samples with x ranging from 0 to 0.22 are synthesized by solid-state reaction method. The x-ray diffraction patterns reveal that YMn1−xZnxO3 samples with low Zn2+ doping concentration (x < 0.1) maintain single phase which show hexagonal structure with space group of P63cm. The temperature dependence of magnetization presents that the magnetic moment at low temperature and the FM transition temperature increase with increasing the doping concentration of Zn2+. Meanwhile, ferromagnetism induced by Zn2+ doping is found to become stronger. EXAFS analysis reveals the in-plane Mn-OP bond length decreases while the out-of-plane Mn-OA bond length keeps almost constant. The weak FM order is ascribed to order-to-disorder effect resulting from the diluted exchange interaction among Mn3+ ions and double-exchange interaction between the mixed valence-sta...