铽镓石榴石单晶的生长、表征及其挥发机理研究

Growth,Characterization and Volatilization Mechanism of Terbium Gallium Garnet Single Crystal

使用预先烧结好的多晶原料,在一定比例的N2和CO2混合气氛下,采用提拉法生长出了高质量的铽镓石榴石（TGG）单晶。采用XRD、ICP和热力学计算进行分析,结果表明,晶体生长过程中的挥发机制为Tb3Ga5O12的分解,分解产物为Tb3GaO6,Ga2O和O2。CO2被Ga2O还原产生O2,抑制了Tb3Ga5O12的分解。TGG单晶的化学分子式存在Tb富集或Ga缺失,为Tb3Ga4.4~4.5O11.1~11.3非化学计量比相。将晶体毛坯加工成2.8mm×10.7mm的晶棒,消光比测试结果表明镀增透膜后消光比平均可提高18.8dB。

High quality terbium gallium garnet（ TGG） single crystals were grown by Czochralski method,using single-phase polycrystalline materials under the atmosphere of mixture of N2 and CO2. X-ray diffraction,Inductive Coupled Plasma Emission Spectrometer（ ICP） and thermodynamic calculations show that the mechanism of volatilization during crystal growth can be attributed to the decomposition of Tb3Ga5O12 to Tb3GaO6,Ga2O,and O2. The CO2 as one of the protecting atmosphere is reduced to O2 by Ga2O,which can inhibit the decomposition of Tb3Ga5O12. The chemical formula for garnet single crystal is Tb enriched or Ga deficient phase of Tb3Ga4. 4-4. 5O11. 1-11. 3. The extinction ratio of crystal rods of 2. 8mm × 10. 7 mm increases an average of 18. 8 dB after AR coating.