Effects of charge compensation by Na+ co-doping for Ce3+ doped LiCaAlF6 single crystals

2010 ◽  
Author(s):  
Y Yokota ◽  
T Yanagida ◽  
N Kawaguchi ◽  
K Fukuda ◽  
A Yoshikawa ◽  
...  
Keyword(s):  
Single Crystals ◽  
Charge Compensation ◽  
Co Doping

Effect of Mg co-doping on scintillation properties of Ce:Gd 3 (Ga, Al) 5 O 12 single crystals with various Ga/Al ratios

2017 ◽  
Vol 468 ◽  
pp. 420-423 ◽  
Author(s):  
Masao Yoshino ◽  
Kei Kamada ◽  
Yasuhiro Shoji ◽  
Akihiro Yamaji ◽  
Shunsuke Kurosawa ◽  
...  
Keyword(s):  
Single Crystals ◽  
Co Doping

Understanding Persistent Luminescence: Rare-Earth- and Eu2+-doped Sr2MgSi2O7

2014 ◽  
Vol 69 (2) ◽  
pp. 171-182 ◽  
Author(s):  
Mika Lastusaari ◽  
Högne Jungner ◽  
Aleksei Kotlov ◽  
Taneli Laamanen ◽  
Lucas C. V. Rodrigues ◽  
...  
Keyword(s):  
Rare Earth ◽  
Band Gap ◽  
Charge Compensation ◽  
Band Gap Energy ◽  
Persistent Luminescence ◽  
Excitation Spectra ◽  
Co Doping ◽  
The Individual ◽  
Initial Intensity ◽  
The Eu

Similar to many other Eu2+,RE3+-co-doped persistent luminescence materials, for Sr2MgSi2O7:Eu2+,RE3+ the initial intensity and duration of persistent luminescence was also found to depend critically on the rare-earth (RE) co-doping. An enhancement of 1 - 2 orders of magnitude in these properties could be obtained by Dy3+ co-doping whereas total quenching of persistent luminescence resulted from the use of Sm3+ and Yb3+. To solve this drastic disparity, the effects of the individual RE3+ ions were studied with thermoluminescence (TL) spectroscopy to derive information about the formation of traps storing the excitation energy. The charge compensation defects were concluded to be the origin of the complex TL glow curve structure. The tuning of the band gap of the Sr2MgSi2O7 host and especially the position of the bottom of the conduction band due to the Eu2+,RE3+ co-doping was measured with the synchrotron radiation vacuum UV (VUV) excitation spectra of the Eu2+ dopant. The model based on the evolution of the band gap energy with RE3+ co-doping was found to explain the intensity and duration of the persistent luminescence.

scholarly journals Ce3+:CaSc2O4 Crystal Fibers for Green Light Emission: Growth Issues and Characterization

2014 ◽  
Vol 1655 ◽  
Author(s):  
Detlef Klimm ◽  
Jan Philippen ◽  
Toni Markurt ◽  
Albert Kwasniewski
Keyword(s):  
Melting Point ◽  
Light Emission ◽  
Green Light ◽  
Optical Emission ◽  
Charge Compensation ◽  
Scanning Calorimetry ◽  
Co Doping ◽  
Emission Growth ◽  
Crystal Fibers ◽  
Alkaline Oxides

ABSTRACTCe3+ is known to show broad optical emission peaking in the green spectral range. For the stabilization of 3-valent cerium in ceramic phosphors such as calcium scandate CaSc2O4, often co-doping with sodium for charge compensation is performed (Na+, Ce3+ ↔ 2 Ca2+). At the melting point of CaSc2O4 (≈2110°C), however, alkaline oxides evaporate completely and co-doping is thus no option for crystal growth from the melt. It is shown that even without co-doping Ce3+:CaSc2O4 crystal fibers can be grown from the melt by laser-heated pedestal growth (LHPG) in a suitable reactive atmosphere. Reactive means here that the oxygen partial pressure is a function of temperature and pO2(T) rises for this atmosphere in such a way that Ce3+ is kept stable for all T. Crystal fibers with ≈1 mm diameter and ≤50 mm length were grown and characterized. Differential thermal analysis (DTA) was performed in the pseudo-binary system CaO–Sc2O3, and the specific heat capacity cp(T) of CaSc2O4 was measured up to 1240 K by differential scanning calorimetry (DSC). Near and beyond the melting point of calcium scandate significant evaporation of calcium tends to shift the melt composition towards the Sc2O3 side. Measurements and thermodynamic calculations reveal quantitative data on the fugacities of evaporating species.

Control of white light emission via co-doping of Dy3+ and Tb3+ ions in LiLuF4 single crystals under UV excitation

2020 ◽  
Vol 31 (4) ◽  
pp. 3405-3414
Author(s):  
Lizhi Fang ◽  
Xiong Zhou ◽  
Jianli Zhang ◽  
Haiping Xia ◽  
Baojiu Chen ◽  
...  
Keyword(s):  
Single Crystals ◽  
White Light ◽  
Light Emission ◽  
White Light Emission ◽  
Co Doping ◽  
Uv Excitation

scholarly journals Superconductivity in Cu Co-Doped SrxBi2Se3 Single Crystals

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3899 ◽  
Author(s):  
Aleksandr Yu. Kuntsevich ◽  
Victor P. Martovitskii ◽  
George V. Rybalchenko ◽  
Yuri G. Selivanov ◽  
Mikhail I. Bannikov ◽  
...  
Keyword(s):  
Critical Temperature ◽  
Transport Properties ◽  
Single Crystals ◽  
Electron Density ◽  
Doping Level ◽  
Carrier Density ◽  
Host Matrix ◽  
Topological Superconductor ◽  
Co Doping ◽  
Co Doped

In this study, we grew Cu co-doped single crystals of a topological superconductor candidate Sr x Bi 2 Se 3 , and studied their structural and transport properties. We reveal that the addition of even as small an amount of Cu co-dopant as 0.6 atomic %, completely suppresses superconductivity in Sr x Bi 2 Se 3 . Critical temperature (∼2.7 K) is rather robust with respect to co-doping. We show that Cu systematically increases the electron density and lattice parameters a and c. Our results demonstrate that superconductivity in Sr x Bi 2 Se 3 -based materials is induced by significantly lower Sr doping level x < 0.02 than commonly accepted x ∼ 0.06 , and it strongly depends on the specific arrangement of Sr atoms in the host matrix. The critical temperature in superconductive Sr-doped Bi 2 Se 3 is shown to be insensitive to carrier density.

Fe centers and charge compensation in ZnWO4 single crystals characterized by ESR and i.r. spectroscopy

1992 ◽  
Vol 53 (7) ◽  
pp. 889-895 ◽  
Author(s):  
A. Watterich ◽  
M. Wöhlecke ◽  
H. Müller ◽  
K. Raksányi ◽  
A. Breitkopf ◽  
...  
Keyword(s):  
Single Crystals ◽  
Charge Compensation

scholarly journals Effects of post-annealing and cobalt co-doping on superconducting properties of (Ca,Pr)Fe2As2 single crystals

2014 ◽  
Vol 505 ◽  
pp. 1-5 ◽  
Author(s):  
T. Okada ◽  
H. Ogino ◽  
H. Yakita ◽  
A. Yamamoto ◽  
K. Kishio ◽  
...  
Keyword(s):  
Single Crystals ◽  
Superconducting Properties ◽  
Co Doping ◽  
Post Annealing

scholarly journals Dissimilar behavior of YAG:Ce and LuAG:Ce scintillator garnets regarding Li+ co-doping

CrystEngComm ◽  
2018 ◽  
Vol 20 (11) ◽  
pp. 1520-1526 ◽  
Author(s):  
M. V. Derdzyan ◽  
K. L. Hovhannesyan ◽  
A. V. Yeganyan ◽  
R. V. Sargsyan ◽  
A. Novikov ◽  
...  
Keyword(s):  
Charge Compensation ◽  
Experimental Methods ◽  
Co Doping ◽  
Compensation Mechanisms

Using a combination of experimental methods, the substitution tendencies of Li+ and involved charge compensation mechanisms are determined and compared in two important similar scintillators, LuAG:Ce and YAG:Ce.

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