KINETICS OF THE FORMATION OF NICKEL FERRITE

Abstract

Previous kinetic studios on nickel ferrite formation by magnetic measurement methods were based on magnetic saturation .ueacuxement of fired stplec. alum and Li used a vibration specimen 'magnetometer which was similar to as described by Loner . Similarly Sconomos and Clevenger applied a compensating coil magnetometer of the Wei so - forrer type to obtain the extent of reaction completed. The present work on the reaction kinetics of nickel ferrite formation is lased on the magnetic susce--pti'bility measurement of the fired aamplea by Gony balance. Zn the present investigation, an attempt has been made to study the effect of temperature on the reaction rate of nickel ferrite foraation. Tea kinetics of this reaction is studied with elaboration on the rate equation which beat fits the a perimeftal data. This thesis has been divided into four chapters. Chapter - I deals with the general int rod acts on to the subject. Literature rpviow is included in Chapter - II. Sesidos the kinetics end mechanism of ferrite formation, seam thermodynamic aspects of the solid solid reaction are also disCussed. It also includes a brief account of the methods of analysis and the factors effecting the kinetics of ferrite fomation. .r MY Chapter - III gives the description of the euperimental set-up and procedure followed in the preeaaet investigation. Dense poitloto of cylindrical ahapo of the etochiometric mixture of nickel o ids end ferric oxide were made by the mounting press, dried and then sintered at eight different temperatures. The kinetic data were obtained by measuring the weight Increased by a semi-micro balance. The chemical analysis of fired samples were also done to confirm the results obtained by the magnetic susceptibility measuremnta., •y Results obtained from the experiments carried out and a• discussion on them constitute the subject matter of chapter. Zip. The experimental data are analysed by four reaction models - Jander, Ginestling - Brounshtlin, modified Ginatling - Drounetein and Kni ger-Ziegler. The activation energies computed by the application of these modbIS are 47.55, 46.26,