Development of novel growth methods for halide single crystals

2017 ◽  
Vol 65 ◽  
pp. 46-51 ◽  
Author(s):  
Yuui Yokota ◽  
Shunsuke Kurosawa ◽  
Yasuhiro Shoji ◽  
Yuji Ohashi ◽  
Kei Kamada ◽  
...  
Keyword(s):  
Single Crystals ◽  
Growth Methods

Low-Temperature Thermal Conductivity of Rubrene Single Crystals: Quantitative Estimation of Defect Density in Bulk and Film Crystals

2009 ◽  
Vol 1154 ◽  
Author(s):  
Yugo Okada ◽  
M. Uno ◽  
Jun Takeya
Keyword(s):  
Thermal Conductivity ◽  
Low Temperature ◽  
Temperature Profile ◽  
Single Crystals ◽  
Gas Phase ◽  
Defect Density ◽  
Quantitative Estimation ◽  
Crystalline Defects ◽  
Growth Methods ◽  
Pronounced Peak

AbstractThermal conductivity of rubrene single crystals is measured for both bulk and film-like crystals down to 0.5 K in order to estimate quantitatively density of crystalline defects through their phonon mean free paths. The temperature profile of the bulk rubrene crystals exhibit pronounced peak at ∼ 10 K in the thermal conductivity as the result of very long mean-free paths of their phonons which indicates extremely low-level defect density in the region of 1015-1016 cm−3 depending on different growth methods. The crystals grown from gas phase tend to have less defects than those grown from solution. It turned out that the film-like crystals have a few times more defect density as the result of the measurement by using newly developed devices for minute crystals.

scholarly journals Recent Developments on Relaxor-PbTiO3 Ferroelectric Crystals

Crystals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 56
Author(s):  
Lkhagvasuren Baasandorj ◽  
Zibin Chen
Keyword(s):  
Crystal Growth ◽  
Single Crystal ◽  
Single Crystals ◽  
Single Crystal Growth ◽  
Practical Applications ◽  
Ferroelectric Crystals ◽  
Recent Developments ◽  
Electromechanical Devices ◽  
Growth Methods

Numerous investigations on the development of the relaxor-PbTiO3 ferroelectric crystals have been carried out since their extraordinary properties were revealed. Recent developments on these crystals have offered further advances in electromechanical applications. In this review, recent developments on relaxor-PbTiO3 crystals and their practical applications are reviewed. The single crystal growth methods are first discussed. Two different strategies, poling and doping, for piezoelectric improvement are surveyed in the following section. After this, the anisotropic features of the single crystals are discussed. Application perspectives arising from the property improvements for electromechanical devices are finally reviewed.

scholarly journals (K,Na)NbO3-based piezoelectric single crystals: Growth methods, properties, and applications

2020 ◽  
Vol 35 (8) ◽  
pp. 990-1016 ◽  
Author(s):  
Jurij Koruza ◽  
Hairui Liu ◽  
Marion Höfling ◽  
Mao-Hua Zhang ◽  
Philippe Veber
Keyword(s):  
Single Crystals ◽  
Growth Methods

Abstract

scholarly journals Direction Controlled Growth of Organic Single Crystals by Novel Growth Methods

10.5772/53037 ◽  
2013 ◽  
Author(s):  
M. Arivanandhan ◽  
V. Natarajan ◽  
K. Sankaranarayanan ◽  
Y. Hayakaw
Keyword(s):  
Single Crystals ◽  
Controlled Growth ◽  
Growth Methods

Growth of Optical Quality 4-Dimethylamino-N-Methyl-4-Stilbazolium Tosylate (DAST) Single Crystals by Novel Technique and their Characterization

2012 ◽  
Vol 584 ◽  
pp. 42-46 ◽  
Author(s):  
M.R. Manikandan ◽  
S.D. Gopal Ram ◽  
G. Ravi
Keyword(s):  
Temperature Gradient ◽  
Single Crystals ◽  
Cluster Formation ◽  
Nucleation And Growth ◽  
Optical Quality ◽  
Growth Technique ◽  
Spontaneous Nucleation ◽  
Novel Technique ◽  
Growth Methods ◽  
Zone Growth

Optical quality 4-dimethylamino-N-methyl-4-stilbazolium tosylate (DAST) crystals have been grown by a novel technique. In conventional growth methods, it was difficult to control the position of spontaneous nucleation, number of nuclei, cluster formation and the nucleation period. Difficulty in the nucleation and growth positioning was effectively solved by the slope nucleation method (SNM) and sizable DAST crystal was grown by two zone growth technique (TZGT) using a seed. Furthermore removal and fixing of seed crystal was difficult in the two zone growth technique. In the present study, we could obtain optical quality bulk DAST crystals by combining SNM and TZGT. The growth rates, size are estimated with respect to temperature gradient and slope shape. The structural, functional and optical analyses were carried for the grown crystals and the results are discussed in detail.

Crystal packing control of a trifluoromethyl-substituted furan/phenylene co-oligomer

2018 ◽  
Vol 74 (5) ◽  
pp. 450-457 ◽  
Author(s):  
Alina A. Sonina ◽  
Igor P. Koskin ◽  
Peter S. Sherin ◽  
Tatyana V. Rybalova ◽  
Inna K. Shundrina ◽  
...  
Keyword(s):  
Optical Properties ◽  
Single Crystals ◽  
Crystal Packing ◽  
Variable Temperature ◽  
X Ray ◽  
Organic Optoelectronics ◽  
Mixed Aggregates ◽  
Growth Method ◽  
Growth Methods ◽  
Trifluoromethyl Groups

Furan/phenylene co-oligomer single crystals are considered as future materials for organic optoelectronics. Here, the effects of trifluoromethyl substituents on the crystallization, structure and optical properties of furan/phenylene co-oligomer 1,4-bis{5-[4-(trifluoromethyl)phenyl]furan-2-yl}benzene are studied systematically. The solution growth methods and physical vapor transport result in the formation of three polymorphs depending on the growth method and the solvent. Single-crystal X-ray analysis reveals the crystal structures to correspond to H-, J- or mixed aggregates. All obtained crystals exhibit high photoluminescence efficiency and have optical properties which strongly depend on the crystal packing. Variable-temperature X-ray powder diffraction analysis shows the thermal transition of two forms (H- and J-aggregates) into a third one (mixed aggregate). Terminal trifluoromethyl groups induce weak intermolecular interactions which control the crystal packing and optical properties of co-oligomer single crystals.

The Microstructure of Shock-Synthesized Diamond

1967 ◽  
Vol 25 ◽  
pp. 324-325
Author(s):  
Lucien F. Trueb
Keyword(s):  
Single Crystals ◽  
Preferred Orientation ◽  
High Magnification ◽  
Texture Pattern ◽  
Shock Process ◽  
New Type ◽  
Diffraction Diagram

A new type of synthetic industrial diamond formed by an explosive shock process has been recently developed by the Du Pont Company. This material consists of a mixture of two basically different forms, as shown in Figure 1: relatively flat and compact aggregates of acicular crystallites, and single crystals in the form of irregular polyhedra with straight edges.Figure 2 is a high magnification micrograph typical for the fibrous aggregates; it shows that they are composed of bundles of crystallites 0.05-0.3 μ long and 0.02 μ. wide. The selected area diffraction diagram (insert in Figure 2) consists of a weak polycrystalline ring pattern and a strong texture pattern with arc reflections. The latter results from crystals having preferred orientation, which shows that in a given particle most fibrils have a similar orientation.

A New Defect in Polyethylene Single Crystals

1973 ◽  
Vol 31 ◽  
pp. 70-71
Author(s):  
E. L. Thomas ◽  
S. L. Sass
Keyword(s):  
Single Crystals ◽  
Screw Dislocation ◽  
Small Distance ◽  
Dipole Model ◽  
Dislocation Dipole ◽  
Chain Folding ◽  
Black And White ◽  
Polymer Crystal ◽  
Different Types

In polyethylene single crystals pairs of black and white lines spaced 700-3,000Å apart, parallel to the [100] and [010] directions, have been identified as microsector boundaries. A microsector is formed when the plane of chain folding changes over a small distance within a polymer crystal. In order for the different types of folds to accommodate at the boundary between the 2 fold domains, a staggering along the chain direction and a rotation of the chains in the plane of the boundary occurs. The black-white contrast from a microsector boundary can be explained in terms of these chain rotations. We demonstrate that microsectors can terminate within the crystal and interpret the observed terminal strain contrast in terms of a screw dislocation dipole model.

Preferential Sputtering of Ni3Al Single Crystals Studied Using Atom-Probe Field-Ion Microscopy and XPS

1981 ◽  
Vol 39 ◽  
pp. 16-17
Author(s):  
M.P. Thomas ◽  
A.R. Waugh ◽  
M.J. Southon ◽  
Brian Ralph
Keyword(s):  
Single Crystals ◽  
Photoelectron Spectroscopy ◽  
Surface Composition ◽  
Depth Profiling ◽  
Analytical Techniques ◽  
Atom Probe ◽  
Probe Field ◽  
Preferential Sputtering ◽  
Argon Ion Bombardment ◽  
Argon Ion

It is well known that ion-induced sputtering from numerous multicomponent targets results in marked changes in surface composition (1). Preferential removal of one component results in surface enrichment in the less easily removed species. In this investigation, a time-of-flight atom-probe field-ion microscope A.P. together with X-ray photoelectron spectroscopy XPS have been used to monitor alterations in surface composition of Ni3Al single crystals under argon ion bombardment. The A.P. has been chosen for this investigation because of its ability using field evaporation to depth profile through a sputtered surface without the need for further ion sputtering. Incident ion energy and ion dose have been selected to reflect conditions widely used in surface analytical techniques for cleaning and depth-profiling of samples, typically 3keV and 1018 - 1020 ion m-2.

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