YIG/bismuth heterogenous thin film with giant magnetooptical effect and preparation method of YIG/bismuth heterogenous thin film

Abstract

The invention discloses a YIG / bismuth heterogenous thin film with a giant magnetooptical effect and a preparation method of the YIG / bismuth heterogenous thin film. The method comprises the steps of growing high-quality single-crystal YIG used as a substrate on gadolinium gallium garnet (GGG) in a crystal direction [111] by liquid phase epitaxy, and growing a thin layer of bismuth on the YIG substrate by molecular beam epitaxy (MBE) to obtain the YIG / bismuth heterogenous thin film. The method is simple and practical, the magneto-optical kerr corner of the obtained YIG / bismuth heterogenous thin film is remarkably increased compared with YIG of a bismuth-free thin film; and compared with replacement doping of bismuth in YIG, the preparation process is simple, a new method is provided for preparation and research of a heterojunction magnetooptical material and has wide application in various fields of optical communication, magnetooptical storage and the like.

Description

technical field [0001] The invention relates to the technical field of new materials, in particular to a giant magneto-optical effect yttrium iron garnet / bismuth heterogeneous thin film and a preparation method thereof. Background technique [0002] In modern social production and science and technology, magnetic materials and magnetic effects have obtained important applications in many aspects. In recent years, with the development of magnetic research, some magnetic effects have been found in some new magnetic materials with great or even breakthrough growth, which are called giant magnetic effects. The research and development of these giant magnetic effect materials not only pose an important challenge to magnetism, but also provide new possibilities for the application of high technology. [0003] Magneto-optical effects are caused by external magnetic fields or changes in the internal magnetic state of materials, especially magnetic materials, that cause the transmit...

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Problems solved by technology

However, as a magneto-optical material, the magneto-optic effect of pure YIG is very weak, and the applied optical communication magneto-optic switch device needs to modify YIG by doping with Bi, Lu, Tm and other elements to enhance its magneto-optic effect, but there is a lattice loss. It is difficult to prepare an ultra-thick film of tens of microns, and the preparation process of liquid phase epitaxy is very complicated and expensive

[0005] Bismuth (Bi) is the last non-radioactive stable element. Its atomic number is large and it is a diamagnetic element, which can greatly enhance the magneto-optic effect. The magneto-optic rotation of YIG comes from Fe 3+ , but Fe 3+ Distribute the tetrahedral centers of 4 ligands or the octahedral centers of 6 ligands, and Bi ions can only enter the dodecahedral centers of 8 ligands because they are too large, so replacing Fe with Bi in YIG is very Difficult, and limited increase in magneto-optical rotation of YIG

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