The size dependence and defect induced room temperature ferromagnetism of ZnO and Zn 1-x-y AlxZyO (Z=Mg/Ni) nanocomposites

Abstract

In the current research, Al-Mg-ZnO and Al-Ni-ZnO nanocomposites were synthesized by using simple soft chemical route. Prepared nanocomposites of Al-Mg-ZnO and Al-Ni-ZnO with capsule shape distributed magnetite nanostructured were carried out under the calcinated at 120 C for 12 h in furnace. The structural morphology and characterization analysis of as prepared nanocomposites was analyzed by XRD, UV–vis. FTIR, PL, TEM, VSM studies. XRD analysis confirmed the highly pure crystallized cubic phases. The XRD peaks show that the crystalline sizes are of the order of 22 nm, 19 nm, and 11nm. Magnetic property of the prepared nanocomposites was discussed in room temperature using VSM measurement. In spite of a number of researchers reporting the effect of codoping ZnO nanoparticles (NPs) with two different metals was modify the properties of the entire system such as enrich in room-temperature ferromagnetism. In this research we tried to by experimentally observed the magnetic properties of a series of soft chemical synthesized Zn1-x-yAlxZyO (Z=Mg/Ni) nanocomposites. Interestingly, it was found that in comparison to un-doped ZnO NPs and co-doped with two different metals. The ferromagnetic signal changes in a co-doped system in which one of the Mg/Ni ions increases the concentration of defects mechanism when Mg/Ni ions exhibited only one oxidation state. The potential role of charge transfer ferromagnetism is involving Mg2+ and Ni2+ ions substituted into ZnO lattice, The origin of magnetism in the nanocomposites is due to exchange interaction between local spin polarized electrons and the conduction electrons. The potential role of charge transfer ferromagnetism involving mixed valence ions and effects defect mechanism was used to explain the room temperature ferromagnetism.