Bubble materials - composition, growth and evaluation

The development of materials for magnetic bubble domain applications and of the techniques for their preparation has been rapid and has achieved considerable success. In this review an attempt has been made to cover some of the important aspects of this complex field. Starting with the compositions used and the reasons for their selection, the methods of preparation are described with particular reference to the process of liquid-phase epitaxy. This is the currently preferred process for the preparation of high quality magnetic layers. For bubble applications the optimization of the magnetic properties and device parameters is also complex. Some discussion of the requirements and of the techniques used for property evaluation is given. The main emphasis is necessarily on the magnetic garnets, which have specific and unique properties for applications as low-loss microwave materials as well as being the best media so far discovered for bubble domain generation and manipulation.