Luminescence spectroscopy of theGd-rich Ce3-, Tb3- and Mn2-doped phosphate glasses
摘要:
Absorption, emission and excitation spectra and luminescence decay kinetics of Na(K)GdCe, NaGdTb and NaGdMn phosphate glasses and their dependence on the temperature (in the 1.7-300 K range) and on the glass composition have been studied. The processes of energy migration through the Gd3+ ions and following energy transfer in Gd3+-impurity pairs have been compared for the three types of the glasses studied. It has been suggested that the Gd3+ --> Tb3+ energy transfer occurs only in the closest pairs through a very short-range exchange interaction, while the Gd3+ --> Ce3+ and Gd3+ --> Mn2+ energy transfer is possible also in more separated pairs mainly due to the longer-range multipolar Gd3+-impurity interaction.
HDEHP assisted solvothermal synthesis of monodispersed REPO<sub>4</sub> (RE = La–Lu, Y) nanocrystals and their photoluminescence properties
作者:Zhen Yang、Guangzhen Yuan、Xiannan Duan、Shuai Liang、Guoxin Sun
DOI:10.1039/c9nj05829j
日期:——
In this paper, a novel method is reported for the preparation of spherical REPO4 particles.
在这篇论文中,报道了一种新颖的方法,用于制备球形REPO4颗粒。
Synthesis of Metal Phosphates Using SiP2O7
作者:Carlos E. Bamberger、George M. Begun、Dale E. Heatherly
DOI:10.1111/j.1151-2916.1983.tb10575.x
日期:1983.11
The reaction of SiP/sub 2/O/sub 7/ with rare-earth fluorides and oxides and with UO/sub2/ proceeds at high temperatures (1000/sup 0/ to 1200/sup 0/C) to convert the rare-earth and uranium compounds to ortho- or pyro-phosphates. In these reactions between intimately mixed powders, very finely segregated SiO/sub2/ is formed and distributed throughout the phosphates. This procedure may be useful for
Facile sonochemical synthesis and photoluminescent properties of lanthanide orthophosphate nanoparticles
作者:Cuicui Yu、Min Yu、Chunxia Li、Xiaoming Liu、Jun Yang、Piaoping Yang、Jun Lin
DOI:10.1016/j.jssc.2008.10.023
日期:2009.2
lanthanide orthophosphate LnPO4 (Ln=La, Ce, Pr, Nd, Sm, Eu, Gd) products have nanorod bundles morphology, while the tetragonal LnPO4 (Ln=Tb, Dy, Ho) samples prepared under the same experimental conditions are composed of nanoparticles. HRTEM micrographs and SAED results prove that these nanostructures are polycrystalline in nature. The possible formation mechanism for LnPO4 (Ln=La–Gd) nanorod bundles
通过在环境温度下对无机盐水溶液进行便捷,快速,高效的超声辐照,系统地合成了均匀的镧系元素正磷酸盐Ln PO 4(Ln = La,Ce,Pr,Nd,Sm,Eu,Gd,Tb,Dy,Ho)纳米颗粒没有任何表面活性剂或模板的条件。X射线衍射(XRD),扫描电子显微镜(SEM),透射电子显微镜(TEM),高分辨率透射电子显微镜(HRTEM),选定区域电子衍射(SAED),光致发光(PL)光谱以及动力学衰减被用来表征样品。扫描电镜(SEM)和透射电镜(TEM)显示六方结构镧系正磷酸盐Ln PO 4(Ln= La,Ce,Pr,Nd,Sm,Eu,Gd)产品具有纳米棒束形态,而在相同实验条件下制备的四方Ln PO 4(Ln = Tb,Dy,Ho)样品则由纳米颗粒组成。HRTEM显微照片和SAED结果证明,这些纳米结构本质上是多晶的。提出了Ln PO 4(Ln = La–Gd)纳米棒束的可能形成机理。还使用相同的合成方法制备了Eu
Systematic Synthesis and Characterization of Single-Crystal Lanthanide Orthophosphate Nanowires
作者:Yue-Ping Fang、An-Wu Xu、Rui-Qi Song、Hua-Xin Zhang、Li-Ping You、Jimmy C. Yu、Han-Qin Liu
DOI:10.1021/ja037280d
日期:2003.12.1
systematic synthesis of lanthanide orthophosphate crystals with different crystalline phases and morphologies. It has been shown that pure LnPO(4) compounds change structure with decreasing Ln ionic radius: i.e., the orthophosphates from Ho to Lu as well as Y exist only in the tetragonal zircon (xenotime) structure, while the orthophosphates from La to Dy exist in the hexagonal structure under hydrothermal
已经开发了一种简单的水热法用于系统合成具有不同晶相和形态的镧系元素正磷酸盐晶体。已经表明纯 LnPO(4) 化合物随着 Ln 离子半径的减小而改变结构:即,从 Ho 到 Lu 以及 Y 的正磷酸盐仅存在于四方锆石(磷钇矿)结构中,而从 La 到 Dy 的正磷酸盐存在在水热处理下的六方结构中。获得的六方结构镧系元素正磷酸盐 LnPO(4)(Ln = La、Ce、Pr、Nd、Sm、Eu、Gd、Tb 和 Dy)产品具有线状形态。相比之下,在相同实验条件下制备的四方 LnPO(4)(Ln = Ho、Er、Tm、Yb、Lu、Y)样品由纳米颗粒组成。得到的六边形LnPO(4) (Ln = La --> Tb)可以转化为单斜独居石结构产物,在空气中900℃煅烧后形貌保持不变(六方DyPO(4)是特例,经煅烧转变为四方DyPO(4)),而(Ho--> Lu, Y)PO(4) 的四方结构通过煅烧保持不变。由此产生的
The conditions of formation of complex lanthanide chromate(VI)-phosphates K2R(CrO4)(PO4) were found and these compounds were synthesized by solid-state synthesis with variation of the starting compounds, the temperature of synthesis (500–800 °C), and the annealing time (6–200 h). These salts are typical of late lanthanides, R = Dy-Lu, Y. Using lutetium derivatives as examples, it was shown that no similar compounds with lithium or sodium are formed. All the complex chromate(VI)-phosphates obtained decompose under static conditions at temperatures above 550 °C. They are isostructural and crystallize in the monoclinic system. The unit cell parameters for thulium, ytterbium, and lutetium compounds were calculated. It is shown by IR spectroscopy that PO4 tetrahedra in the crystal lattice of potassium lanthanide chromate(VI)-phosphates are substantially distorted, whereas the CrO4 tetrahedra retain the regular tetrahedron symmetry (T d ).