VUV–UV Photoluminescence Spectra of Strontium Orthophosphate Doped with Rare Earth Ions

2002 ◽  
Vol 167 (2) ◽  
pp. 435-440 ◽  
Author(s):  
Hongbin Liang ◽  
Ye Tao ◽  
Qiang Su ◽  
Shubin Wang
2001 ◽  
Vol 62 (4) ◽  
pp. 807-810 ◽  
Author(s):  
Sun Xiaolin ◽  
Hong Guangyan ◽  
Dong Xinyong ◽  
Xiao Dong ◽  
Zhang Guilan ◽  
...  

1999 ◽  
Vol 604 ◽  
Author(s):  
Katsuhisa Tanaka ◽  
Tsuguo Ishihara ◽  
Koji Fujita ◽  
Kazuyuki Hirao

AbstractIntense triboluminescence has been observed in rare-earth-doped aluminosilicates such as BaAl2Si2O8and SrAl2Si2O8doped with Eu2+, Tb3+, or Dy3+. The triboluminescence is caused by the excitation of and emission from rare-earth ions doped in the crystals. A discrepancy in the wavelength of maximum emission intensity between triboluminescence and photoluminescence spectra is observed for the 4f65d-4f7 transition of Eu2+, whereas the peak positions and the relative intensities of emission lines in triboluminescence and photoluminescence spectra are almost the same as each other for the 4f-4f transitions of Th3+ and Dy3+. This is because the 5d levels, which are more significantly affected by ligand fields than the 4f levels, contribute to the transition of Eu2+. It is thought that the difference in local environment around the Eu2+ between on the fractured surface and within the bulk brings about the discrepancy between triboluminescence and photoluminescence spectra


2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
M. A. Marzouk ◽  
H. A. ElBatal ◽  
Y. M. Hamdy ◽  
F. M. Ezz-Eldin

Glasses with the Na2O–ZnO–P2O5 composition and doped with single CeO2, Sm2O3, or mixed dopants were melted and studied. Collective optical, photoluminescence, and FT-infrared spectral studies were carried out. CeO2-doped glasses show two extra UV absorption bands due to Ce4+ and Ce3+ ions while Sm2O3-doped samples reveal pronounced peaks collected into two segments from 367 to 472 nm and from 950 to 1623 nm which are characteristic of absorption from Sm3+ ions. The mixed dopants glasses show combined UV-visible–near-IR absorption peaks due to cerium (Ce4+, Ce3+) ions and samarium (Sm3+) ions. The photoluminescence spectra (PL) of the single CeO2-doped and Sm2O3-doped glasses and even the mixed dopant sample reveal luminescence spectra after excitation which are characteristic of the rare-earth ions. The intensities for both excited or emitted peaks are found to increase with the increase of the rare-earth percent. FTIR spectra of the glasses show pronounced vibrational peaks related to phosphate groups (Q2 and Q3 units) in accordance with the P2O5 percent (70 mol %).


2011 ◽  
Vol 131 (9) ◽  
pp. 1840-1847 ◽  
Author(s):  
Aierken Sidike ◽  
Rahman Abu Zayed Mohammad Saliqur ◽  
Jui-Yang He ◽  
Gong Lan-Xin ◽  
K. Atobe ◽  
...  

Author(s):  
N. M. P. Low ◽  
L. E. Brosselard

There has been considerable interest over the past several years in materials capable of converting infrared radiation to visible light by means of sequential excitation in two or more steps. Several rare-earth trifluorides (LaF3, YF3, GdF3, and LuF3) containing a small amount of other trivalent rare-earth ions (Yb3+ and Er3+, or Ho3+, or Tm3+) have been found to exhibit such phenomenon. The methods of preparation of these rare-earth fluorides in the crystalline solid form generally involve a co-precipitation process and a subsequent solid state reaction at elevated temperatures. This investigation was undertaken to examine the morphological features of both the precipitated and the thermally treated fluoride powders by both transmission and scanning electron microscopy.Rare-earth oxides of stoichiometric composition were dissolved in nitric acid and the mixed rare-earth fluoride was then coprecipitated out as fine granules by the addition of excess hydrofluoric acid. The precipitated rare-earth fluorides were washed with water, separated from the aqueous solution, and oven-dried.


2020 ◽  
Vol 10 (2) ◽  
pp. 152-156 ◽  
Author(s):  
Muhammad Hanif bin Zahari ◽  
Beh Hoe Guan ◽  
Lee Kean Chuan ◽  
Afiq Azri bin Zainudin

Background: Rare earth materials are known for its salient electrical insulation properties with high values of electrical resistivity. It is expected that the substitution of rare earth ions into spinel ferrites could significantly alter its magnetic properties. In this work, the effect of the addition of Samarium ions on the structural, morphological and magnetic properties of Ni0.5Zn0.5SmxFe2-xO4 (x=0.00, 0.02, 0.04, 0.06, 0.08, 0.10) synthesized using sol-gel auto combustion technique was investigated. Methods: A series of Samarium-substituted Ni-Zn ferrite nanoparticles (Ni0.5Zn0.5SmxFe2-xO4 where x=0.00, 0.02, 0.04, 0.06, 0.08, 0.10) were synthesized by sol-gel auto-combustion technique. Structural, morphological and magnetic properties of the samples were examined through X-Ray Diffraction (XRD), Field-Emission Scanning Electron Microscope (FESEM) and Vibrating Sample Magnetometer (VSM) measurements. Results: XRD patterns revealed single-phased samples with spinel cubic structure up to x= 0.04. The average crystallite size of the samples varied in the range of 41.8 – 85.6 nm. The prepared samples exhibited agglomerated particles with larger grain size observed in Sm-substituted Ni-Zn ferrite as compared to the unsubstituted sample. The prepared samples exhibited typical soft magnetic behavior as evidenced by the small coercivity field. The magnetic saturation, Ms values decreased as the Sm3+ concentration increases. Conclusion: The substituted Ni-Zn ferrites form agglomerated particles inching towards more uniform microstructure with each increase in Sm3+ substitution. The saturation magnetization of substituted samples decreases with the increase of samarium ion concentration. The decrease in saturation magnetization can be explained based on weak super exchange interaction between A and B sites. The difference in magnetic properties between the samples despite the slight difference in Sm3+ concentrations suggests that the properties of the NiZnFe2O4 can be ‘tuned’, depending on the present need, through the substitution of Fe3+ with rare earth ions.


Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3717
Author(s):  
Jae-Young Jung ◽  
Soung-Soo Yi ◽  
Dong-Hyun Hwang ◽  
Chang-Sik Son

The precursor prepared by co-precipitation method was sintered at various temperatures to synthesize crystalline manganese tungstate (MnWO4). Sintered MnWO4 showed the best crystallinity at a sintering temperature of 800 °C. Rare earth ion (Dysprosium; Dy3+) was added when preparing the precursor to enhance the magnetic and luminescent properties of crystalline MnWO4 based on these sintering temperature conditions. As the amount of rare earth ions was changed, the magnetic and luminescent characteristics were enhanced; however, after 0.1 mol.%, the luminescent characteristics decreased due to the concentration quenching phenomenon. In addition, a composite was prepared by mixing MnWO4 powder, with enhanced magnetism and luminescence properties due to the addition of dysprosium, with epoxy. To one of the two prepared composites a magnetic field was applied to induce alignment of the MnWO4 particles. Aligned particles showed stronger luminescence than the composite sample prepared with unsorted particles. As a result of this, it was suggested that it can be used as phosphor and a photosensitizer by utilizing the magnetic and luminescent properties of the synthesized MnWO4 powder with the addition of rare earth ions.


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