Li^+,Er^(3+)共掺杂Gd_2O_3半透明陶瓷的显微结构与上转换发光研究

Microstructure and Upconversion Luminescence of Li, Er-codoped Gd_2O_3 Translucent Ceramics

采用低温燃烧法制备出Li+,Er3+共掺杂Gd2O3纳米粉体,将粉体压片成型后在1500℃真空条件下烧结10 h成功制备出Li+,Er3+共掺杂Gd2O3半透明陶瓷。对粉体和半透明陶瓷样品的晶体结构、形貌、显微结构和上转换发光特性等用XRD,TEM,SEM,FL等手段进行了表征和研究。结果表明:Li+和Er3+均匀地溶解于Gd2O3晶格之中。粉体颗粒近似球形,粒径约20~30 nm。烧结后半透明陶瓷致密度高,未见气孔存在,透光率高;在980 nm LD激发下有两个峰值波长分别为561 nm(绿光)和658 nm(红光)上转换发光带,分别对应4S3/2/2H11/2→4I15/2和4F9/2→4I15/2跃迁;Li+的掺杂抑制了Gd2O3由立方到单斜的相变,且使陶瓷样品中Er3+的上转换发光强度显著增强,红绿光之比大大提高。

Gd2O3： 1% Er,5% Li nanocrystalline powder was prepared by low temperature combustion method. The crystal structure and morphology were analyzed by means of XRD and TEM. Gd2O3： Li,Er translucent ceramics was obtained by sintering at 1500 ℃ in vacuum for 10 h. The micrograph of unpolished surface and fracture surfaces showed that the sintered Gd2O3： Li,Er ceramics with grain size at 3 ~ 4 μm had homogeneous microstructure.Under the excitation of 980 nm diode laser,very strong green and red upconversion emissions from Er3 ＋ions were observed. The results showed that the upconversion intensity emitted by Er3 ＋and the transmittance of Gd2O3： Li,Er ceramics in the visible spectral region were greatly enhanced and improved when Li＋was codoped.