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

Abstract

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. Dedicated to Professor K. W. Benz on the occasion of his 65th birthday.

Studies on the growth of epitaxial bismuth-substituted iron garnet on gadolinium gallium garnet single crystals by pulsed laser deposition

“…The magnetic and MO properties have been intensely studied by these groups, too. But not so many reports on structural properties or growth mechanisms have been published yet [2,20].…”

“…In general, garnet films such as Y 3 Fe 5 O 12 (YIG) are grown by liquid phase epitaxy (LPE) [2] on Gd 3 Ga 5 O 12 (GGG) substrates. In order to increase the Faraday rotation Bi substitutes Y [3][4][5].…”

Pulsed Laser Deposition and Growth Studies of Bi3Fe5O12 on Gd3Ga5O12 and SiO2

“…The substrates were cleaned previous to the ablation process in an ultrasonic bath of acetone and isopropyl alcohol followed by rinsing with pure water. Up to four substrates (5x5 mm 2 ) were glued onto the holder (10x10 mm 2 ) with conductive silver to ensure sufficient thermal contact.…”

Preparation of nanocrystalline bismuth-substituted yttrium iron garnet films with enhanced Faraday magneto-optical figure of merit by pyrolysis of coprecipitated hydroxide slurry

“…Many methods have been used to prepare single-or polycrystalline Bi-substituted garnet films, including liquid-phase film epitaxy (LPE) [5], coprecipitate pyrolysis [6,7], solid-phase vacuum deposition of laser ablation [8] and RF sputtering [9]. Although the pyrolysis method cannot produce single-crystalline films, it has certain technical and economical advantages: (1) the film chemical composition can be adjusted precisely, simply by changing the ion content ratio in the starting solution; (2) no sophisticated vacuum system is required; (3) no expensive substrate such as Gd 3 Ga 5 O 12 (GGG) is necessary, thus the substrate area limitation can be overcome.…”