γ-LiAlO_2晶体生长、改性和热学性质研究

Study on the growth, modification and thermal properties ofγ-LiAlO_2 single crystals

采用快速提拉法生长出了透明、完整的γLiAlO2晶体,但是晶体的高熔点和易挥发性限制了γLiAlO2晶体质量.采用气相传输平衡法(vaportransportequilibrationtechnique,VTE)工艺对晶体改性,半高宽(FWHM)值从116.9arcsec降至44.2arcsec,继续升高VTE处理温度至1300℃,FWHM值反而升高至55.2arcsec.快速提拉法生长出来晶体,[100]方向和[001]方向的热膨胀系数分别为17.2398×10-6K,10.7664×10-6K.经过三步VTE处理后[100]和[001]方向热膨胀系数降至16.6539×10-6K和10.1784×10-6K.

Transparent and crack-free γ-LiAlO2 single crystal was grown by quick Czochralski technique. However, high melting point and easy volatilization degraded the quality of the crystal. The fall with at half maximum （FWHM） value dropped from 116.9aresec to 44.2arcsec when the crystal was modified by vapor transport equilibrium（VTE） technique. But when the temperature of VTE was 1300 ℃ , the FWHM value increased to 55.2aresec. The [ 100 ]-orientation thermal expansion coefficient of the as-grown crystal was 17.6798 × 10^-6/K, while that along the [001 ]-orientation was 10.7664 × 10^-6/K. After three VTE treatments, the corresponding thermal expansion coefficients decreased to 16.6539 × 10^-6/K and 10.1784 × 10^-6/K, respectively.