LD泵浦激光晶体Nd:GGG原料制备及结构分析

采用共沉淀方法,以金属Ga和Gd2O3为起始原料,以氨水为沉淀剂,制备了GGG多晶.测量了共沉淀方法制备的GGG多晶、固相反应法制备的Nd:GGG多晶以及提拉法生长的GGG、Nd:GGG晶体的X射线衍射谱(XRD),利用图解外推法计算了晶格参数.共沉淀方法制备的GGG多晶原料较固相法制备的Nd:GGG晶格参数小,可能是固相制备过程中Ga组分挥发导致Gd3 取代了Ga3 位以及Nd3 占据了部分的Gd3 位,从而使晶格参数变大.同时就提拉法生长的Nd:GGG晶体和GGG晶体的晶格参数进行比较发现,Nd:GGG晶体的晶格参数较纯GGG晶体的晶格参数大,说明在Nd:GGG晶体中Nd3 占据了部分的Gda 位.另外,晶体的晶格参数较多晶粉末的晶格参数大,分析认为这可能也是由于Ga组分的挥发导致Gd3 占据了Ga3 位所引起.这些实验结果说明Ga组分挥发在原料制备过程和晶体生长过程中都可能存在,因此应在制备原料和晶体生长等各个环节中考虑Ga组分的挥发.采用液相共沉淀方法制备有利于抑止Ga组分的挥发.

Study on raw material preparation and structure of LD-pumped Nd:GGG laser crystal

GGG polycrystalline material was prepared by co-precipitation method with the metal Ga and Gd2O3 as the starting materials and aqueous ammonia as the preprecipitator. The X-ray diffraction spectra of GGG polycrystalline material prepared by co-precipitation method ,Nd:GGG prepared by solid-state method and the crystals GGG and Nd: GGG grown by Czochralski method were measured. Their lattice parameters were computed by extrapolation method. The lattice parameter of GGG polycrystalline material is smaller than that of Nd:GGG polycrystalline material, it is probably because the Gd3+ substitute Ga3+ and Nd3+substitute Gd3+ partly. Meanwhile, The lattice parameter of Nd:GGG crystal is larger than that of GGG crystal, from the result we know that Nd3+ substitute Gd3+. In addition, the lattice parameters of crystals are bigger than those of polycrystalline materials, which is probably caused by Gd3+ substitute Ga3+ due to Ga component vaporization. These results show that Ga component vaporization maybe exists not only in the preparation of polycrystalline materials but also in the crystal growth, so the Ga component vaporization should be considered in polycrystalline material preparation and crystal growth. The vaporization of Ga component can be controlled by using co-precipitation method.