含钪石榴石Nd:GSGG晶体的原料制备、晶体生长及结构研究

Study on raw material preparation method, crystal growth and structure of the scandium-containing garnet Nd:GSGG

提拉法生长的Nd:GSGG是性能优良的激光晶体,在固体强激光领域有重要的运用前景。采用液相共沉淀法制备了GSGG的前驱物,将前驱物在较低的温度下烧结,获得了GSGG多晶原料,用提拉法生长了无散射、气泡、云层、无开裂的(?)26 mm×45 mm的含钪石榴石Nd:GSGG晶体。用X射线衍射对GSGG的共沉淀前驱物在不同烧结温度下的相变情况进行了研究,表明在900℃烧结温度下, GSGG前驱物即可反应形成GSGG多晶,这比固相法合成GSGG料的反应温度低了200℃。同时,用X射线衍射对GSGG多晶、Nd:GSGG单晶的结构进行了研究,采用最小二乘法,以f(θ)=sinθ-sin1-Tθ(T=20)为外推函数,计算了GSGG多晶和Nd:GGG单晶的晶格参数,分别为1.257547 nm、1.256163 nm。它们之间的晶格参数差异可能是由于Ga组分的不同所引起的。

Nd：GGG grown with Czochralski method is a very promising laser crystal used in the strong lasers. The precursor of GSGG was prepared by coprecipitatiom method, and polycrystalline material of GSGG was obtained at the lower sintered temperature. Scandiumcontaining garnet Nd：GSGG of Ф26 mm×45 mm, which are free of scattering, air bubbles, cloud layer and crack, was grown by Czochralski method. The phase transition of co-precipitating precursors of GSGG sintered at the different temperatures was studied by X-ray diffraction, which indicated that the precursors were converted into the polycrystalline GSGG at 900 ℃. The phase transition temperature is 200 ℃ lower than that of solid state reaction method. Meanwhile, the structure of the polycrystalline GSGG and single crystal Nd：GSGG were studied by X-ray diffraction. Their lattice parameters were computed by the least square method with the extrapolation function f（θ） = sin θ-sin^1-T θ（T = 20）, which are 1.257547 nm and 1.256163 nm, respectively. It results from the difference of the ingredient Ga Nd：GSGG. is possible that the lattice parameter difference in the polycrystalline GSGG and single crystal Nd：GSGG.