Modulation of the Structural, Magnetic, and Dielectric Properties of YMnO by Cu Doping.

The lower valence compensation of YMnCuO ( = 0.00, 0.05, and 0.10) is prepared by the solid-state reaction, and the effects of divalent cation Cu-doping on the construction and magnetic and dielectric attributes of multiferroic YMnO are systemically researched. Powder X-ray diffraction shows YMnCuO has a single-phase hexagonal construction with a space group as the parent YMnO, and lattice parameters decrease systematically as Cu concentration increases. Using the scanning electric microscope, structure morphologies analysis shows that the mean grain size varies between 1.90 and 2.20 μm as Cu content increases. YMnCuO magnetization increases as Cu doping concentration increases, and the antiferromagnetic transition temperature declines from 71 K for = 0.00 to 58 K for = 0.10. The valence distributions of Mn ions conduce to the modified magnetic attributes. Due to Cu substitution, the dielectric loss and dielectric constant decline as frequency increases from 400 to 700 K, showing representative relaxation behaviors. Indeed, that is a thermally activated process. In addition, the peak of the dielectric loss complies with the Arrhenius law. The relaxation correlates to the dipole effect regarding carrier hopping between Mn and Mn, and also correlates to oxygen vacancies generated by Mn.