Indian Journal of Science and Technology

Abstract

Objective Methods/Statistical Analysis : Multivariate statistical analysis viz. Cluster Analysis (CA) was performed to validate the experimental findings. : The (In0.955 CO0.045 )2 O3 samples were concocted by the typical solid state reaction route. The resulting materials were pelletized and sintered in hydrogen atmosphere. Subsequently, hydrogenated pallets were dehydrogenated by further heating for 7h in air.The sampleswere thoroughly characterized using X-ray diffraction. FULLPROF Program is used to refine the crystalline structures. Magnetic hysteresis loops were evaluated using Vibrating Sample Magnetometer (VSM) at room temperature. Hierarchical CA was accomplished on the normalized data set (samples) by means of the Ward’s method, using Euclidean distances as a measure of similarity. Findings: The X-Ray Diffraction (XRD) study confirmed the formation of cubic bixbyite structure for In2 O3 , (In0.955 Co0.045 )2 O3 and (In0.955 Co0.045 )2 O3 :H samples. The magnetic study at Room Temperature (RT) confirms that pure In2 O3 is diamagnetic and turns to paramagnetic upon Co doping. Furthermore, it was found that the ferromagnetic property is evidently induced by post-annealing in hydrogen atmosphere. This investigation also depicts that after further long heating, the sample again resumes its paramagnetic behaviour. CA grouped the five samples into three groups based on similarities of magnetic characteristics as diamagnetic, paramagnetic and ferromagnetic. The statistical study validates the experimental findings. Improvements/Applications: CA helps in the corroboration of data matrices of experimental findings to better understand the influence of hydrogen annealing on magnetic properties of cobalt doped indium oxide.

Keywords: Cluster Analysis, Hydrogen, In2 O3 , Magnetic Properties, Post-Annealing