Recent advances of bismuth garnet materials research for bubble and magneto-optical applications

Abstract

Epitaxially grown bismuth-substituted iron garnet films of composition R <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3-x</inf> Bi <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</inf> Fe <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5-y</inf> M <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">y</inf> O <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">12</inf> with <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x \leq 2.5</tex> (R=Y,Gd,Lu,Yb and M = Al,Ga,Si) are considered with respect to the temperature and concentration dependence of their magnetic and magneto-optical properties. In particular, the magnetization, Curie temperature, uniaxial anisotropy, optical absorption and Faraday rotation reveal pronounced changes with increasing bismuth content. Special attention is paid to the control of the uniaxial growth-induced anisotropy caused by the ordering of the bismuth ions via the site preference mechanism. This ordering process is characterized by a strong dependence on the growth conditions such as the melt composition and the supercooling allowing the variation of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">K\min{u}\max{g}</tex> in the range <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">O&lt;K\min{u}\max{g} \leq 2.10^{4}</tex> Jm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-3</sup> . The magneto-optical properties exhibit a linear increase with increasing bismuth content.