Optical Floating Zone Method Growth of YIG Magneto-Optical Crystals

doi:10.16553/j.cnki.issn1000-985x.2026.0051

Abstract

Abstract: Yttrium iron garnet （Y₃Fe₅O₁₂， YIG） crystals possess exceptional magneto-optical properties， rendering pivotal for optical communication and photonic integration. Herein， YIG single crystals were grown via the optical floating zone method， and the influence of growth atmosphere on optical quality of YIG single crystal was systematically investigated. The results show that phase-pure garnet structures are successfully obtained under both air and different oxygen partial pressure atmospheres. Crucially， crystals grown under pure O₂ atmosphere exhibit superior transmittance performance in the infrared band， and its transmittance is close to the theoretical value （~75%）. This is primarily due to the higher oxygen partial pressure during the growth process， which effectively inhibits the valence change of Fe³⁺. Fe 2p X-ray photoelectron spectroscopy analysis further reveals that the relative content of Fe²⁺ is as high as 62% （mole fraction） in grown crystals under air atmosphere， but the relative content of Fe²⁺ is reduced to 9% （mole fraction） in grown crystals under pure O₂ atmosphere， which directly confirms the effective inhibition of oxygen partial pressure on the valence change of Fe³⁺ from the chemical state level， thus facilitating preparation of high-quality magneto-optical crystals. The magneto-optical performance test at 1 386 nm further confirms that the prepared YIG crystal has good magneto-optical modulation performance， and its Faraday rotation angle can reach 225 （°）/cm. This study provides a feasible path for the preparation of high-quality iron-based garnet crystals， which is of great significance for promoting the development of corresponding magneto-optical crystal functional devices.

Key words: YIG; magneto-optical crystal; crystal growth; optical floating zone method; growth atmosphere

CLC Number:

FU Zhaoshu, WANG Shuxian, LU Dazhi, WU Kui, YU Haohai, ZHANG Huaijin. Optical Floating Zone Method Growth of YIG Magneto-Optical Crystals[J]. Journal of Synthetic Crystals, 2026, 55(9): 1371-1376.

Figures/Tables 6

Fig.1 Physical photo of sintered YIG feed rod （a） and XRD pattern of standard ratio region in sintered YIG feed rod （b）

Fig.2 Photo of molten zone morphology during YIG crystal growth process in pure O2 atmosphere （a） and photographs of YIG crystals and processed samples grown under different oxygen partial pressure atmospheres （b）

Fig.3 XRD patterns of YIG crystals grown under different oxygen partial pressure atmospheres

Fig.4 Infrared transmittance curves （a） and absorption coefficients （b） of YIG crystals grown under different oxygen partial pressure atmospheres

Fig.5 Fe 2p XPS of sample grown under air atmosphere （a）， Fe 2p XPS of sample grown under pure O2 atmosphere （b） and relative content of Fe2+ and Fe3+ obtained from peak fitting analysis （c）

Fig.6 Variation curve of Faraday rotation angle for YIG crystal grown under pure O2 atmosphere with magnetic field

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