Department of Physics, Indian Institute of Technology (BHU), Varanasi, 221005, India.
Dalton Trans. 2014 Mar 28;43(12):4770-8. doi: 10.1039/c3dt52786g.
A facile auto-combustion route is used for the synthesis of Gd(3+) (2, 5, 7 and 10 at%) co-doped CaMoO4:Eu nanoparticles. X-ray diffraction study suggests that as-prepared samples have extra impurity phases in addition to main tetragonal phase of CaMoO4, and such extra phases decrease as the annealing temperature increases from 600 to 900 °C. The crystal structure has been analysed using Rietveld program. It has space group I4₁/a (88) and Z = 4 (number of CaMoO4 formula units per unit cell). Average crystallite sizes of as-prepared, 600 and 900 °C annealed samples for 2 at% Gd(3+) are found to be ~33, 48 and 61 nm, respectively. The lattice strains of 5 at% Gd(3+) co-doped CaMoO4:Eu for as-prepared and 900 °C are 0.001 and 0.002, respectively. Fourier transform infrared spectroscopy gives the absorption bands at ~815 and 427 cm(-1), which are related to asymmetric stretching and bending vibrations of MoO4(2-) tetrahedron. Particle morphology is studied using scanning and transmission electron microscopy (SEM and TEM), and aggregation of particles is found. X-ray photoelectron spectroscopy (XPS) is utilized to examine the oxidation states of metal ions/oxygen and oxygen ion vacancies in Gd(3+) co-doped CaMoO4:Eu. With an increase in Gd(3+) concentration, peaks corresponding to the Gd(3+) (2p(3/2) and 2p(5/2)) binding energy could be detected.
一种简便的自燃烧法被用于合成 Gd(3+)（2%、5%、7%和 10%）共掺杂的 CaMoO4:Eu 纳米粒子。X 射线衍射研究表明，除了 CaMoO4 的四方主相之外，所制备的样品还有额外的杂质相，而这些额外的相随着退火温度从 600°C 增加到 900°C 而减少。晶体结构通过 Rietveld 程序进行了分析。它具有空间群 I4₁/a（88）和 Z = 4（每个晶胞中的 CaMoO4 分子式单位数）。对于 2%Gd(3+)，发现未退火、600°C 和 900°C 退火的样品的平均晶粒尺寸分别约为 33nm、48nm 和 61nm。5%Gd(3+)共掺杂 CaMoO4:Eu 的未退火和 900°C 时的晶格应变分别为 0.001 和 0.002。傅里叶变换红外光谱在~815 和 427cm(-1)处给出吸收带，这与 MoO4(2-)四面体的不对称伸缩和弯曲振动有关。使用扫描和透射电子显微镜（SEM 和 TEM）研究了粒子形态，发现了粒子的聚集。X 射线光电子能谱（XPS）用于检查 Gd(3+)共掺杂 CaMoO4:Eu 中金属离子/氧和氧离子空位的氧化态。随着 Gd(3+)浓度的增加，可以检测到对应于 Gd(3+)（2p(3/2)和 2p(5/2))结合能的峰。
