通过Bi^(3+)发光特征判定“争议”格位——以Ca_2MgSi_2O_7∶Bi^(3+)荧光粉为例（英文）  

Verifying the “Controversial”Available Sites via Typical Bi^(3+) Luminescent Feature:Exemplarily Based on the Ca_2MgSi_2O_7∶ Bi^(3+) Phosphor

作　　者：康逢文[1] 韩瑾[1] 彭明营[1] 

机构地区：[1]华南理工大学材料科学与工程学院发光材料与器件国家重点实验室广东省教育厅中德光子材料与器件研究中心,广州510641

出　　处：《应用化学》2016年第12期1420-1427,共8页Chinese Journal of Applied Chemistry

基　　金：Supported by the National Natural Science Foundation of China(No.51322208,No.51672085);Guangdong Natural Science Foundation for Distinguished Young Scholars(No.S20120011380);the Department of Education of Guangdong Province(No.2013gjhz0001);Fundamental Research Funds for the Central Universities(No.2015ZP0004);Key Program of Guangzhou Scientific Research Special Project(No.201607020009);the Hundred,Thousand and Ten Thousand Leading Talent Project in Guangdong Program for Special Support of Eminent~~

摘　　要：在以往的研究工作中,人们经常关注给定基质具有多个格位所对应多发光中心的光致发射。取决于所掺杂的基质,多个格位的晶体化合物应该可以提供相应的多发光中心,但某些化合物有时只会表现一个发光中心,由此产生"争议性"发光中心。据以往研究,以稀土离子掺杂而为人所知的经典镁黄长石(Ca_2MgSi_2O_7)长余辉化合物具有"争议性"Ca格位。为此,在本文中以非稀土离子(Bi^(3+))特有的发光特性从侧面来研究Ca_2MgSi_2O_7化合物中的"争议性"Ca格位问题。结果表明,在250和276 nm激发波长激发下,所有的Bi^(3+)掺杂Ca_2MgSi_2O_7样品均有峰位位于582和350 nm的两个Bi^(3+)特征发射带。结合晶体结构分析,光谱结果表明,Ca_2MgSi_2O_7∶Bi^(3+)荧光粉具有对应于六配位和八配位的两个不同Ca2+格位的两个Bi^(3+)发光中心,即,Bi^(3+)(Ⅰ)(~582 nm)和Bi^(3+)(Ⅱ)(~350 nm)发光中心。此外,光谱分析进一步表明,Bi^(3+)(Ⅰ)与Bi^(3+)(Ⅱ)具有单向的能量传递,而且,发现这两个发光中心所对应的相对发射强度是依赖于激发波长和Bi^(3+)掺杂浓度。实验证明了Ca_2MgSi_2O_7晶体化合物具有两个Ca格位,而不是有些工作中所讨论的一个Ca格位。本文工作可以为已知或未知的具有"争议性"格位的晶体化合物的验证提供新的借鉴。Multi-photoemissions from multi-luminescent centers that correspond to multi available sites in a given crystal are frequently noticed in previous works. Depending on the exact type of dopant built into,compounds having multi available sites should correspondingly offer multi luminescent centers,but some kinds of such compounds sometimes exhibit only one luminescent center,exhibiting the＂controversial＂centers. According to previous works,the akermanite（ Ca_2MgSi_2O_7）,which has been known as the classical afterglow host for a long term,belongs to this type of compounds having the＂controversial＂Ca sites. Here we report on utilizing the typical luminescent behavior of the non-rare-earth（ non-RE） ion（ Bi^（3＋）） to explore the issues of＂controversial＂Ca sites in Ca_2MgSi_2O_7crystal. Our results show that the excitation bands centering at 250 nm and 276 nm can pump all samples of Ca_2MgSi_2O_7∶ Bi^（3＋）to exhibit dual Bi^（3＋）-related photoemissions centering at 582 nm and ~ 350 nm,respectively. In combination with the crystal structure analysis,the spectral results indicate that there are dual Bi^（3＋）luminescent centers[denoted as Bi^（3＋）（Ⅰ） and Bi^（3＋）（ Ⅱ） ] at two different Ca2 ＋sites coordinating with six- and eight- oxygen atoms in the Ca_2MgSi_2O_7host. Surprisingly,the spectral results support the existence of the energy transfer from Bi^（3＋）（ Ⅰ） to Bi^（3＋）（ Ⅱ） and the process is found to be unidirectional. Further analysis indicated that the relative emission intensity of 582 nm and~ 350 nm derived from Bi^（3＋）（Ⅰ） and Bi^（3＋）（ Ⅱ） centers is tightly relied on the incident excitation wavelength and the Bi^（3＋）doping contents. Our results clearly prove that there are two available Ca sites instead of only one Ca site in Ca_2MgSi_2O_7crystal. Because of the reason,this work provides a new insight into verifying the available sites in some unknown or / and well-known crystals from another

关 键 词：铋（Ⅲ） 镁黄长石 荧光粉 能量传递 争议格位 

分 类 号：O611[理学—无机化学]