scholarly journals Development of the growth technique on cerium bromide single crystal by Halide-micro-pulling-down method

2017 ◽  
Vol 52 (6) ◽  
pp. 1600401 ◽  
Author(s):  
Tomoki Ito ◽  
Yuui Yokota ◽  
Shunsuke Kurosawa ◽  
Kei Kamada ◽  
Yuji Ohashi ◽  
...  
2020 ◽  
Author(s):  
Keishiro Yamashita ◽  
Kazuki Komatsu ◽  
Hiroyuki Kagi

An crystal-growth technique for single crystal x-ray structure analysis of high-pressure forms of hydrogen-bonded crystals is proposed. We used alcohol mixture (methanol: ethanol = 4:1 in volumetric ratio), which is a widely used pressure transmitting medium, inhibiting the nucleation and growth of unwanted crystals. In this paper, two kinds of single crystals which have not been obtained using a conventional experimental technique were obtained using this technique: ice VI at 1.99 GPa and MgCl<sub>2</sub>·7H<sub>2</sub>O at 2.50 GPa at room temperature. Here we first report the crystal structure of MgCl2·7H2O. This technique simultaneously meets the requirement of hydrostaticity for high-pressure experiments and has feasibility for further in-situ measurements.


Author(s):  
Phan Gia Le ◽  
Huyen Tran Tran ◽  
Jong-Sook Lee ◽  
John G. Fisher ◽  
Hwang-Pill Kim ◽  
...  

AbstractCeramics based on (Na1/2B1/2)TiO3 are promising candidates for actuator applications because of large strains generated by an electric field-induced phase transition. For example, the (1−x)(Na1/2Bi1/2)TiO3-xSrTiO3 system exhibits a morphotropic phase boundary at x = 0.2–0.3, leading to high values of inverse piezoelectric constant d*33, which can be further improved by the use of single crystals. In our previous work, single crystals of (Na1/2B1/2)TiO3-SrTiO3 and (Na1/2B1/2)TiO3-CaTiO3 were grown by the solid state crystal growth technique. Growth in the (Na1/2B1/2)TiO3-SrTiO3 system was sluggish whereas the (Na1/2B1/2)TiO3-CaTiO3 single crystals grew well. In the present work, 0.8(Na1/2Bi1/2)TiO3-0.2(Sr1−xCax)TiO3 single crystals (with x = 0.0, 0.1, 0.2, 0.3, 0.4) were produced by the solid state crystal growth technique in an attempt to improve crystal growth rate. The dependence of mean matrix grain size, single crystal growth distance, and electrical properties on the Ca concentration was investigated in detail. These investigations indicated that at x = 0.3 the matrix grain growth was suppressed and the driving force for single crystal growth was enhanced. Replacing Sr with Ca increased the shoulder temperature Ts and temperature of maximum relative permittivity Tmax, causing a decrease in inverse piezoelectric properties and a change from normal to incipient ferroelectric behavior.


2014 ◽  
Author(s):  
Craig D. Nie ◽  
James A. Harrington ◽  
Yuan Li ◽  
Eric G. Johnson ◽  
Elizabeth F. Cloos ◽  
...  

2013 ◽  
Vol 1538 ◽  
pp. 405-410
Author(s):  
Shaoping Wang ◽  
Aneta Kopec ◽  
Andrew G. Timmerman

ABSTRACTA ZnO single crystal is a native substrate for epitaxial growth of high-quality thin films of ZnO-based Group II-oxides (e.g. ZnO, ZnMgO, ZnCdO) for variety of devices, such as UV and visible-light emitting diodes (LEDs), UV laser diodes and solar-blind UV detectors. Currently, commercially available ZnO single crystal wafers are produced using a hydrothermal technique. The main drawback of hydrothermal growth technique is that the ZnO crystals contain large amounts of alkaline metals, such as Li and K. These alkaline metals are electrically active and hence can be detrimental to device performances. In this paper, results from a recently developed novel growth technique for ZnO single crystal boules are presented. Lithium-free ZnO single crystal boules of up to 1 inch in diameter was demonstrated using the novel technique. Results from crystal growth and materials characterization will be discussed.


Author(s):  
A. Ruby

L-Valine zinc acetate (LVZA) was synthesized and its solubility was estimated in the solvent of double distilled water. Single crystals of LVZA were grown by slow evaporation solution growth technique. The cell parameters were obtained by single crystal X-ray diffraction study. Functional groups of LVZA were identified by FTIR analysis. UV-vis-NIR spectral studies showed the optical nature of LVZA. Kurtz powder technique revealed the SHG efficiency of LVZA. Thermal properties of the grown LVZA crystal were studied from TGA/ DTA and DSC spectrum. Vickers’s mechanical hardness values were found for the grown crystal.


1990 ◽  
Vol 01 (03n04) ◽  
pp. 347-367 ◽  
Author(s):  
KAZUHITO FURUYA ◽  
YASUYUKI MIYAMOTO

GaInAsP/InP organometallic vapor phase epitaxy (OMVPE) is widely used for the fabrication of lasers and detectors used in optical communication. Here we describe the apparatus and growth technique of OMVPE and point out important growth conditions to obtain device quality single-crystal materials. Our research includes the use of OMVPE for the study of quantum-well lasers, ballistic-transport electron devices and nanometer heterostructures.


2020 ◽  
Vol 49 (2) ◽  
pp. 181-186 ◽  
Author(s):  
V. Chithambaram ◽  
T. S. Franklin Rajesh ◽  
Geetha Palani ◽  
E. Ilango ◽  
B. Deepanraj ◽  
...  

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