I thank my supervisor Professor M.R.J. Gibbs for this opportunity and for his assistance through this project. Unfortunately, due to illness, he was not available for periods of this study, and I therefore wish to especially thank Professor Gillian Gehring (2^nd supervisor), Dr. Harry Blythe, John Bishop and the rest of the departmental staff for providing the time to discuss my work in his absence. This support and supervision was invaluable.

Thanks are also due to the past and present members of the group who have always been there as friends and colleagues. A special mention to Dr. Richard Watts for all his support and helpful discussions. I also thank Michael Cooke, Werner Karl and Dr. Hilary Hatton for the all the good times we have experienced along with their helpful discussions about work and life in general.

I thank all the Technical Staff, both in physics and the Central Mechanical Workshop for their expertise and in the preparation of apparatus used during this study. A special thanks must be said to J.C. Newell (John), J. Kelly (JK), R. Nicholson (Dickie), M. Bentley (Martin) and T. Addison (Terry), for their help, expertise and just being good friends.

I also thank the members of departmental office (past and present) for all their assistance and co-operation.

A very special thanks to Maureen Webster not only for her assistance as the physics librarian, but being there as friend.

Finally, I wish to thank my mum and dad for all their encouragement and financial support during the course of this work, and to my two brothers, Nimman and Imran, for all their encouragement and their views on the world around us.