Journal ArticleDOI
Preparation and structure refinement of Eu3+ doped CaMoO4 nanoparticles
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TLDR
The high resolution TEM suggests a change in orientation of the crystal on annealing up to 900 °C as well as the solubility limit of Eu(3+) ions at the Ca(2+) sites is up to 3 at.Abstract:
The nanoparticles of CaMoO4 : Eu3+ (Eu3+ = 0, 1, 3, 5, 7, 10 at. %) are prepared at low temperature (150 °C for 3 h) using urea hydrolysis in ethylene glycol. These are characterized by X-ray diffraction (XRD), infrared spectroscopy (IR) and transmission electron microscopy (TEM). From XRD study, it was found that the solubility limit of Eu3+ ions at the Ca2+ sites is up to 3 at. % and above this, phase segregation occurs. In combination with Rietveld analysis, its crystal structure was found to be tetragonal phase (space groupI41/a (88) and Z = 4 (number of CaMoO4 formula units per unit cell). Unit cell parameters and bond distances are calculated. The average crystallite sizes of as-prepared, 500 and 900 °C heated samples are found to be 20, 35 and 70 nm, respectively. The lattice strain is found to be 0.003–0.005. From IR study, the bands at 820 and 441 cm−1 are assigned to asymmetric stretching and bending vibrations of the MoO42− tetrahedron, respectively. From TEM study, the shape of particle was found to be spherical. The high resolution TEM suggests a change in orientation of the crystal on annealing up to 900 °C.read more
Citations
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Journal ArticleDOI
Defect correlated fluorescent quenching and electron phonon coupling in the spectral transition of Eu3+ in CaTiO3 for red emission in display application
Sudipta Som,A.K. Kunti,Vinod Kumar,Vijay Kumar,Somrita Dutta,M. Chowdhury,S. K. Sharma,Jacobus J. Terblans,Hendrik C. Swart +8 more
TL;DR: In this article, a series of CaTiO3 phosphors doped with trivalent europium (Eu3+) and codoped with potassium (K+) ions were prepared by the solid state reaction method and X-ray diffraction results revealed that the obtained powder phosphors consisted out of a single-phase orthorhombic structure and it also indicated that the incorporation of the dopants/co-dopants did not affect the crystal structure.
Journal ArticleDOI
Improved luminescence and temperature sensing performance of Ho3+–Yb3+–Zn2+:Y2O3 phosphor
Anurag Pandey,Vineet Kumar Rai +1 more
TL;DR: It is found that by using fluorescence intensity ratio technique, appreciable sensitivity for temperature measurement can be achieved from the present phosphor material, which indicates its applicability as a high temperature sensing probe.
Journal ArticleDOI
Luminescence properties of Tb3+-doped CaMoO4 nanoparticles: annealing effect, polar medium dispersible, polymer film and core–shell formation
TL;DR: The luminescence intensity is improved significantly after core-shell formation due to extent of decrease of non-radiative rates arising from surface dangling bonds and capping agent and to improve crystallinity.
Journal ArticleDOI
Behaviour of electric and magnetic dipole transitions of Eu3+, 5D0 → 7F0 and Eu–O charge transfer band in Li+ co-doped YPO4:Eu3+
TL;DR: The effect of Li+ co-doping on the photoluminescence properties of YPO4:Eu is discussed in this article, where interesting properties such as the presence of intermediate bands, shifting of the Eu-O CTB to a lower wavelength, variation in intensities of magnetic and electric dipole transitions of Eu3+ and shift of 5D0 → 7F0 to higher energy with increasing excitation wavelengths are observed.
Journal ArticleDOI
Luminescence properties of Eu3+ doped CaMoO4 nanoparticles
Abdul K. Parchur,R. S. Ningthoujam,Shyam Bahadur Rai,Gunadhor S. Okram,Ram Asaray Singh,Mohit Tyagi,S. C. Gadkari,Raghvendra Tewari,Rajesh K. Vatsa +8 more
TL;DR: The luminescence intensities and lifetimes increase significantly with increasing heat-treatment temperature of the doped samples, and this is attributed to the reduction of H(2)O from the surface of the particles and a non-radiative process after heat treatment.
References
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Elements of X-ray diffraction
TL;DR: In this article, the authors present a chemical analysis of X-ray diffraction by Xray Spectrometry and phase-diagram Determination of single crystal structures and phase diagrams.