Technique for controlling the properties of magnetic garnet films

Experimental procedures relevant to the growth of liquid phase epitaxial magnetic garnet films are discussed. These include substrate etching and cleaning, and techniques for obtaining uniform films with low densities of magnetic defects. A melt composition, designed to avoid the occurrence of orthoferrite or magnetoplumbite, is tabulated for the growth of Sm
0.4
Y
2.6
Ga
1.2
Fe
3.8
O
12
and a new melt preparation technique is described. The phenomenon of melt compositional "drift" is introduced and the contributing mechanisms are explained. Melt drift causes systematic changes in the properties of successive films grown from a single melt. An empirical melt control scheme has been developed to counteract the effects of drift so that more than 50 films have been grown from a single melt with their properties maintained within device specifications. Data from 1250 films grown using the melt control scheme have been collected and analyzed.