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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-state of Mn3+ and Mn4+ by hole doping of Zn2+. [ABSTRACT FROM AUTHOR]

An immediate quenching using liquid N2 is applied for synthesizing the 5d transitionmetal oxides (Sr1-xCax)2IrO4 (0 ≤ x ≤ 0.15) single phase. X-ray diffraction together with Rietveld refinement shows that the lattice parameters along a and c directions and the bond angle of Ir-O2-Ir decrease with the increase of Ca content. X-ray Absorption Fine Spectroscopy measurements prove that the valence of Ir and the average Ir-O bond-length substantially remain unchanged with Ca content increasing in the phase. The effective magnetic moment μeff and Néel temperature TN decrease simultaneously with increased Ca content. Electrical resistivity shows complex temperature dependence behavior, which follows the three-dimensional variable range hopping behavior at low temperature, Arrhenius-type behavior at middle-temperature, and a weak electronic localization in quasi-two-dimensional at high temperature. [ABSTRACT FROM AUTHOR]