Structural Confinement Assisted a Robust Superparamagnetic State in MgNi 2 O 3 and MgNi 1.5 Co 0.5 O 3 Nanoparticles at Room Temperature

In this study, ideal spherical-shaped cubic metal oxide nanoparticles of < 30 nm in size were prepared by a citric acid sol-gel combustion method. The detailed structural analysis and microscopic techniques clearly support the existing grade of structural confinement effect in MgNi2O3 and MgNi1.5Co0.5O3. Temperature-dependent magnetisation studies at various applied fields revealed a moderate change of TB near room temperature by distinct particle size. Magnetic crystalline anisotropy and energy barrier density theoretical model results suggested the importance of innermost magnetic particle stability-aided spin orientation with a fascinating magnetic moment in superparamagnetic region exerted by Ni and Co remarkably postured as a significant part of these nanoparticles.