Yu Jingbo, Hu Lili, Shen Yujing, Ren Jinjun
Key Laboratory of Materials for High Power Laser, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, P. R. China.
Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China.
Inorg Chem. 2021 Apr 19;60(8):5868-5881. doi: 10.1021/acs.inorgchem.1c00283. Epub 2021 Apr 7.
A series of glasses with composition 60NaPO-(40-)CdF-YF-ErO were synthesized via melt-quenching methods and subsequently heat-treated to obtain upconversion luminescent glass ceramics containing NaYF:Er crystals. Hexagonal and/or cubic NaYF crystals were controlled to be bred in the glasses by changing the glass composition. The structure evolution driven by crystallization was characterized using advanced solid-state nuclear magnetic resonance (SSNMR) techniques. The SSNMR results reveal that the Y/Na ratio determines the crystalline phases of NaYF precipitated in this glass system. Y attracts extra F ions from P and Cd during crystallization because of its stronger ability to attract F ions, leading to most Y ions being crystallized into the NaYF crystals. The paramagnetic broadening effect of the Er ions on NMR signals as well as the upconversion luminescence results indicate that, before crystallization, most Er ions are surrounded by oxygen within the glasses; however, after crystallization, almost all of them enter the NaYF crystals. On the basis of this local structure investigation, a composition design strategy is developed to obtain highly efficient upconversion luminescent glass ceramics.
通过熔融淬火法合成了一系列组成为60NaPO-(40-)CdF-YF-ErO的玻璃，随后进行热处理以获得含有NaYF:Er晶体的上转换发光玻璃陶瓷。通过改变玻璃组成，控制在玻璃中生长出六方和/或立方NaYF晶体。利用先进的固态核磁共振（SSNMR）技术对结晶驱动的结构演变进行了表征。SSNMR结果表明，Y/Na比决定了在该玻璃体系中析出的NaYF的晶相。由于Y吸引F离子的能力更强，在结晶过程中Y会从P和Cd中吸引额外的F离子，导致大多数Y离子结晶进入NaYF晶体。Er离子对NMR信号的顺磁加宽效应以及上转换发光结果表明，在结晶之前，大多数Er离子被玻璃中的氧包围；然而，结晶后，几乎所有的Er离子都进入了NaYF晶体。基于这种局部结构研究，开发了一种成分设计策略以获得高效的上转换发光玻璃陶瓷。
