Russian Mineralogical Society
2nd International Conference "Crystallogenesis and Mineralogy"
Flux growth, composition and morphology of rare earth doped KLu(WO4)2 crystals

RMS-DPI code:  2007-1-36-1
Scientific session:  Session 3. Synthesis of crystalline materials and experimental mineralogy
Author listing:  Wang J., Zhang H., Zhao H., Koporulina E.V., Leonyuk N.I.
Principal author:  Wang Jiyang
Language:  English
Abstract - Summary 
(short description):
Potassium rare earth tungstate single crystals are highly efficient materials for diode-pumped solid-state lasers, Raman shifters, planar waveguide devices and other industrial applications. In this paper, a correlation between growth conditions, composition, physical properties and morphology of crystals grown is discussed for several representatives of this family.
Potassium lutetium tungstate crystals have been successfully grown by top seeded solution growth method. Using BFDH law and PBC theory, an ideal habit of these crystals has been calculated. The crystal structure of KLu(WO4)2 was refined. Absorption and fluorescence spectra of Tb:KLu(WO4)2 were measured at room temperature. The specific heat is a little lower in comparison with Yb:KLu(WO4)2 at 90°C. Spectral and luminescent properties of the Sm:KLu(WO4)2 crystal have been investigated. Based on the Judd–Ofelt theory, the spectral parameters have been obtained as the followings: the phenomenological intensity parameters Ω t are: Ω 2 = 15.728×10-20 cm2, Ω 4 = 4.223× 10-20 cm2 and Ω 6 = 2.839×10-20 cm2, irradiative transition probabilities Aj.j’ and oscillator strengths Pj.j’. The irradiative lifetime of levels 4G5/2 is 748 ms. In addition, the values of integrated emission cross sections are also calculated.
Growth mechanisms of KLu(WO4)2 crystals have been investigated using ex situ atomic force microscopy. 2D nuclei and spiral hillocks are simultaneously imaged on the {110} faces. It was presumed that both screw dislocation sources and 2D nucleus on the {110} faces as well as simple flow of steps on {310} faces are responsible for the faceting and habit of KLu(WO4)2 crystals grown from K2W2O7 based high-temperature solutions. A special dislocation sources with the Burgers vectors perpendicular to the {110} crystal face of b = 8 are also discussed.
The composition of crystals grown was measured by the microprobe analyzer CAMECA SX-50 with an accuracy of ± 0.02-0.03wt%. The segregation coefficients (K) were calculated basing the following equation K=Ccryst/CdissKReW, where Ccryst is Re content in grown crystals and CdissKReW is Re concentrations in the corresponding crystalline substances of the fluxed melt. It was found that the average K value vary from 0.80 to 1.02.
This research was supported by the grants of NSFC ## 50590401 and 0611120336, and RFBR&NSFC # 05-05-39003.
RMS-DPI code:  2007-1-36-1
Proceeedings volume 
in the RMS catalogue:
Crystallogenesis and Mineralogy
Pages:  152-153
File of proceedings 
 330 K
Status:  printed
Accepted:  09/05/2007
Published on-line:  05/01/2008
Permanent address of publication:
Contact author(s):  Wang, Jiyang

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