Interfacial effect: magnetism in pure ZrO2, ZnO and SiO2 coated core/shell/shell hybrid nanoparticles

Abstract

We report the room temperature magnetic behavior of pure and dual shells ZnO as well as SiO 2 coated ZrO 2 core-shell nanoparticles. All the samples, viz., ZrO 2 , ZrO 2 /ZnO and ZrO 2 /ZnO/SiO 2 nanocrystallites have been successfully synthesized by chemical precipitation method. The XRD studies confirm the tetragonal structure for pure Zirconia and hexagonal wurtzite structure for ZnO coated ZrO 2 samples. Average size of nanocrystallites has been observed to increase due to the incorporation of the shells over ZrO 2 . Studies of SEM, TEM and EDAX were used to determine the morphology, size and presence of elements in the ZrO 2 nanocrystallites. The existence of SiO 2 on ZrO 2 @ZnO was characterized by FT-IR measurement. The VSM studies have shown that the dual shells ZnO as well as SiO 2 coated ZrO 2 samples exhibit S-shaped paramagnetic behavior of the samples with little variations. The paramagnetic ordering of this core-shell nanostructure was mainly attributed to oxygen vacancies and also to the minor impurity phases in Zirconia and ZnO lattices.

Synthesis and Characterization of ZnO:NiO Nanocomposites Prepared by Phyllanthus Emblica Fruit Extract Assisted Green Method

“…4 ZnO nanostructures have recently gained significant interest for their possible application in high-charge storage capacitors due to high electrical permittivity. Moreover, Zinc oxide owns a larger direct energy band gap 5 and large exciton binding energy of 3.37 eV and 60 meV, 6,7 respectively which is extremely economical for largescale production. ZnO has interesting properties in catalysts, sensors, supercapacitors, spintronics, 8 etc.…”

Regulation of the magnetic behavior by adjusting oxygen stoichiometry in ZrOx film

“…On the contrary, it is proposed that anion defects can also induce FM in material systems such as ZnO [4] and SnO 2 [5] . In recent years, FM was also observed in oxides doped with "nonmagnetic" elements [6] as well as undoped oxides [7] , which opened an extensive controversy about whether FM is intrinsic or due to extrinsic origins such as metallic clusters and inadvertent contamination.…”