Preparation and Properties of Magnetic Garnet Films Containing Divalent and Tetravalent Ions

Abstract

The relevant phase equilibrium data necessary to grow garnet films containing divalent and tetravalent ions by liquid phase epitaxy are presented. The effects of melt composition on film magnetic properties and film composition are presented as is the influence of growth kinetics on the film magnetic parameters. Work on the false(Y,normalSm,normalCa)3false(normalGe,normalFe)5O12 system is stressed. A coupled distribution coefficient is defined which adequately describes the Ca2+‐Ge4+substitution. The effect of melt depletion on magnetic properties is discussed and data presented to indicate the magnitude of the effect observed in the false(Y,normalSm,normalCa)3false(normalGe,normalFe)5O12 system. An example of the propagation characteristics observed in the false(Y,normalSm,normalCa)3false(normalGe,normalFe)5O12 system is also shown. A technique for controlling the temperature dependence of the collapse field in LPE films is presented. The use of Lu3+ as both a dodecahedral and octahedral substituent is shown to lead to a system flexible enough to meet most of the present device requirements.

Crystallographic site-occupancy refinements in thin-film oxides by channelling-enhanced microanalysis

“…Within the limitations of the assumptions of the technique, it can be inferred that the substitution of these rare-earth additions in the octahedral sites of this crystal structure is highly probable, with a probability ->95%. These results are in good agreement with earlier studies (Suchow & Kakta, 1972;Blank, Nielsen & Biolsi, 1976), particularly for the distribution of the small rare-earth ion Lu 3+, which can easily be accommodated in the smaller octahedral site.…”

Modifying the temperature dependence of magnetic garnet film coercivity by etching

“…In spite of the strong site selectivity of these ions, a certain proportion of them occupy octahedral sites. 17 Chemical analysis is able to show the total amount of an element in the material, regardless of its distribution between the sublattices. However, from the viewpoint of magnetic properties, only substituting ions occupying tetrahedral sites are active, and any rearrangement of them between sublattices leads to a modification of magnetic properties.…”