Garnet layers prepared by liquid phase epitaxy for microwave and magneto-optical applications - a review

The magnetic iron garnets possess two outstanding properties, an excellently narrow linewidth of the ferromagnetic resonance and a magneto-optical activity that is without competition when the iron garnet is substituted with bismuth. Here the growth of bismuth substituted iron garnet layers with a bismuth content of up to 1.8 formula units is reported. The influence of solution compositions and undercooling on the growth and bismuth incorporation is discussed. Morphological instabilities due to misfit stress are avoided by the use of lattice-matched substrates. Two applications of iron garnet layers, namely a electronically controllable magnetostatic delay line for the communication technology in the GHz range and magneto-optic garnet sensor layers for real-time visualisation of eddy currents with high spatial resolution for the non-destructive evaluation are presented. Furthermore the detection, measurement, and visualisation of magnetic fields by magneto-optic garnet layers are reviewed.