掺钕氟化钇锂多晶料的合成与晶体生长

Synthesis of Nd∶LiYF_4 Polycrystalline Materials and Crystal Growth

采用干法(稀土氧化物与无水HF气体高温反应)合成Nd∶LiYF4(Nd∶YLF)多晶料。通过X射线衍射仪对多晶料的物相结构进行表征,确定了多晶料合成最佳工艺参数。发现稀土氟化物原料中氧化物杂质的存在对生长晶体有很大影响,直接采用未经处理的氟化物原料生长晶体,会在晶体表面出现白色包裹物。因此,在HF气氛下,经1 200℃热处理才能去除残留在氟化物原料中的氧化物杂质,保证生长晶体的质量。实验确定了生长YLF晶体的最佳组分配比是LiF与YF3的摩尔比为53∶47。以最佳组分配比,采用提拉法生长了Nd∶YLF晶体。结果表明:以最佳组分配比生长的Nd∶YLF晶体具有高的纯度和光学性能;在808nm二极管激光器泵浦下,位于1 047和1 053nm处的发射峰(4 F3/2→4 I11/2)均有较强的荧光发射。

Nd∶ LiYF4 （Nd∶ YLF） polycrystalline raw materials were synthesized via high temperature reactions between the rare earth oxides and anhydrous HF gas.The phase structure and the synthesis parameters of polycrystalline materials were analyized by Xray diffraction.It is found that the existence of oxide impurities in rare earth fluoride as raw material has a great in fluence on the growth of crystals.The crystals grown with untreated fluoride raw material appear white inclusions on the crystal surface.The residual oxide impurities in the fluoride raw material can be removed after heat treatment at 1 200 ℃ in HF atmosphere,which can guarantee the quality of the growth crystal.The optimal component proportion of YLF crystal growth can be obtained at the LiF to YF3 mole ratio of 53∶47.The Nd∶ YLF crystal was grown via the Czochralski method at the optimal component proportion.The results indicate that the Nd∶ YLF crystal has a high purity and superior optical properties.The main emission peaks of Nd∶ YLF crystal pumped under 808 nm diode laser is located at 908 nm （4F3/2→4I9/2）,1 047 and 1 053nm （4F3/2→4I11/2）,and 1 321 and 1 313 nm （4F3/2→4I13/2）,respectively.