Nd:GSAG纳米粉体的合成、晶体结构及光谱

Synthesis,Crystal Structure and Spectral Properties of Nd:GSAG Nano-powder

采用共沉淀法,以NH4OH为沉淀剂制备了1%(原子分数)Nd3+:Gd3Sc2Al3O12前驱体,并在不同的温度下对前驱体进行煅烧。用X射线衍射(XRD)和红外光谱(FT-IR)技术对前驱体及煅烧后粉体的结构、微观形貌进行了研究。结果表明,前驱体在1000℃下煅烧可获得纯GSAG多晶相粉体。用X射线衍射宽化法估算粉体的平均晶粒尺寸为25 nm。通过X射线粉末衍射,用Rietveld全谱拟合方法对晶体结构进行了精修,得到1000℃下煅烧所得Nd:GSAG粉体的晶胞参数为a=b=c=1.24164(5)nm,α=β=γ=90°。在室温下,测定了激发波长为808nm的发射谱和检测波长为942 nm的激发谱。另外,测定了942和1064 nm处的荧光衰减曲线,并用单指数函数进行了拟合,得到对应的荧光寿命分别为0.529和0.512 ms。

The 1% （atom fraction） Nd3＋ ._Gd3Sc2Al3012 precursor was prepared by co-precipitation method with NH4OH as the precipitant. The precursor and the powders sintered at different temperatures were characterized by X-ray diffractometry （XRD） and infrared spectra （IR）. It was found the precursor sintered at 1000 ℃ was transformed to pure GSAG phase, whose average grain sizes was estimated to be about 25 nm by Seherrer＇s formula. The structure of the powder sin- tered at 1000 ℃ was refined by the Rietveld refinement method. The lattice parameters were a = b = c = 1. 24164 （5） nm, α =β = γ = 90° The emission spectrum under 808 nm excitation and the excitation spectrum monitored at 942 nm were measured at room temperature. The fluorescence decay curves at 942 nm and at 1064 nm were also measured and fitted with a single exponential function, and it showed that the corresponding fluorescence lifetimes were 0. 528 and 0. 512 ms.