Preparation and Characterization of NiFe2O4 and CoFe2O4 Thin Films for Electrochemical Supercapacitor Applications

Abstract

This work reports the preparation and characterization of NiFe2O4 and CoFe2O4 thin films by computerized chemical spray pyrolysis for electrochemical supercapacitor applications. The films have been characterized by X-ray diffraction, field emission scanning electron microscopy, energy dispersive analysis by X-rays, optical absorption and electrical resistivity measurements to study the physical properties. The supercapacitive performance of NiFe2O4 and CoFe2O4 thin films has been studied through cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy. newlineThis thesis comprises seven chapters. First chapter deals with general introduction and provides basic information and highlights the importance of energy storage, types and development of supercapacitors, literature survey and motivation of present work. Second chapter describes the basics of thin films, deposition and characterization methods. newlineThird chapter deals with the preparation and characterization of NiFe2O4 thin films at various substrate temperatures using the chemical spray pyrolysis method. The effect of substrate temperature on structural, morphological, compositional, optical, electrical and electrochemical properties of NiFe2O4 thin films has been described. Whereas in chapter IV the effect of solution concentration used for preparation of NiFe2O4 thin films on structural, morphological, compositional, optical, electrical and electrochemical properties has been studied. newlineChapter V deals with the preparation and characterization of CoFe2O4 thin films at various substrate temperatures using chemical spray pyrolysis. The investigation on the effect of substrate temperature on physical properties such as phase formation, surface structure, elemental analysis, optical absorbance, electrical properties and electrochemical properties has been described. In Chapter VI, the influence of solution concentration used for preparation of CoFe2O4 thin films on the material structure, surface texture, elemental composition, opti