NaREO_2(RE=Lu,Y)的制备及其结构的研究  

Preparation and structure of NaREO_2 (RE=Lu,Y)

作　　者：郭如旺[1] 郭常新[1] 吴笛[1] 

机构地区：[1]中国科学技术大学物理系,合肥230026

出　　处：《物理学报》2008年第1期607-614,共8页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:50332050)资助的课题~~

摘　　要：用高温固相法制备了NaLuO2和NaYO2晶体粉体.制备纯相的NaLuO2粉体晶体困难,而制备纯相NaYO2粉体晶体相对容易.为了测定NaLuO2产物中含少量Lu2O3不纯相的量,用X射线衍射绝标法确定了样品中这两者的重量比和谱峰比的关系,得到了绝标法常数kNLua2LuO3O2为3.8.通过改变反应条件(温度、时间、配比、以及助熔剂等)的二次煅烧法找到了制得了纯相的NaLuO2粉体晶体的最佳反应条件是将摩尔比200∶100∶7的反应物Na2O2和Lu2O3及助熔剂Na3PO4混合,在双坩埚中于850℃的马弗炉中煅烧3h,产物水洗后再加Na2O2二次煅烧.制得的NaLuO2粉末晶体为六角结构,空间群为R3m,晶胞参数(a=0.3335nm,c=1.6545nm).对NaLuO2的XRD分析表明,实验中NaLuO2样品的XRD谱比JCPDS23-0684(NaLuO2)卡片中XRD谱多一条(006)面衍射峰,且卡片中标定的(007),(111)和(117)峰的指定应纠正为(104),(110)和(024).Eu3+分别掺入NaLuO2和NaYO2中,由于Eu3+在晶格中所处对称性位置不同,使得它们的发光光谱不同.NaLuO2:Eu3+(Eu3+的点对称性有反演中心i)发光主峰在590nm附近是Eu3+的5D0→7F1跃迁,为磁偶极发射;而NaYO2:Eu3+(Eu3+的点对称性无反演中心i)发光主峰在610nm附近是Eu3+的5D0→7F2跃迁,为电偶极发射.NaLuO2 and NaYO2 powder crystals were prepared by the conventional solid state reaction method. It is more difficult to synthesize pure NaLuO2 powder crystals than NaYO2. To monitor the quantity of Lu2O3 in the NaLuO2 sample, we calculated the relation between weight ratio and XRD peak absolute intensity ratio of Lu2O3 to NaLuO2 by X-ray diffraction method, and obtained the constant （K^Lu2O3 NaLuO2= 3.8）. Pure NaLuO2 powder crystals were obtained by optimizing reaction conditions （sintering temperature, reaction time, raw material molar ratio and fluxes） in a two-step method. The best reaction condition was found to be that the mixture of Na202 , Lu2O3 and Na3 PO4 at a molar ratio of 200：100：7 is filled into a small inner ceramic crucible which is placed inside a larger outer ceramic crucible and sintered at 850℃ for 3 h. The sample has pure hexagonal structure （space group R3m, lattice constant a = 0.3335 nm, c = 1.6545 nm） . XRD pattern of NaLuO2 in this experiment indicated that there is an additional diffraction peak （006） compared with JCPDS23-0684, and the labeled （007）, （ 111 ） and （117） peaks should be corrected to （104）, （110） and （024） according to the Bragg reflection conditions of hexagonal system. Eu^3＋ doped NaLuO2 and NaYO2 have different emission spectra, which indicates that Eu^3＋ occupy different symmetric sites. The main peak of the former （having inversion centre i） is at about 590 nrn, corresponding to the magnetic dipole transition of Eu^3＋ （^5D0→^7F1）, and the later （no inversion centre i） is at about 610 nm, corresponding to the electric dipole transition of Eu^3＋（^5D0→^7F2）.

关 键 词：NaLuO2 NaYO2 LU2O3 XRD定量分析 稀土发光 

分 类 号：O482[理学—固体物理]