scholarly journals Growth, XRD, Mechanical, Optical and SHG Studies of L-Lysine L-Tartaric Acid Crystals

2019 ◽  
Vol 8 (2) ◽  
pp. 57-62
Author(s):  
C. Anbulakshmi ◽  
P. Selvarajan ◽  
S. Selvaraj

Single crystals of L-lysine L-tartaric acid (LLLT) were grown by solution method using double distilled water as the solvent. The grown crystals LLLT were subjected to characterization studies like XRD studies, mechanical studies, optical studies and SHG studies. From XRD studies, it is ascertained that LLLT crystal crystallizes in monoclinic structure. The grown crystal has high transmittance in the visible region and it has high optical band gap. The mechanical parameters like hardness, work hardening coefficient, yield strength, stiffness constant, brittleness index, corrected hardness and resistance pressure of LLLT crystal have been evaluated by using Vickers microhardness method. The relative SHG efficiency of LLLT crystal has been determined by Kurtz-Perry powder technique.

1968 ◽  
Vol 12 (5) ◽  
pp. 186-188 ◽  
Author(s):  
S. K. Kurtz ◽  
T. T. Perry ◽  
J. G. Bergman

Author(s):  
M. Saravanan

The crystals N-(2-chlorophenyl)-(1-propanamide) (NCP) appropriate for nonlinear optical (NLO) and electro–optic appliances were grown full-fledged by the slow cooling method. The solubility and metastable zone width range of NCP specimen were studied. The specimen crystallizes in the monoclinic crystal system with noncentrosymmetric space group of P21. The crystal morphology study also elucidates supplementary excellence of the as-grown NCP crystal. The optical precision in the whole visible region was found to be superior for NLO claim. The crystallinity of the full-fledged crystal is determined by etching and HRXRD. Laser harm threshold and photoluminescence studies delegate the grown crystal comprises extremely less imperfections. The mechanical deeds of NCP sample at assorted temperatures were examined to decide the hardness solidity of the grown specimen. The piezoelectric behavior and the comparative second harmonic generation for assorted particle sizes of the material were also deliberate. The third-order nonlinear ocular possessions of NCP crystal specimen were determined by [Formula: see text]-scan method. The optical homogeneity of the solitary crystal was assessed using customized channel spectrum technique. The thermal structures of NCP solitary crystal have been studied using photopyroelectric method. The half-wave voltage of the full-fledged crystal was intended from the electro–optic experimentation. Photoconductivity nature of the grown crystal outlined consummate inducing dipoles due to strong incident radiation and further revealed the nonlinear deeds of the grown material.


2019 ◽  
Vol 221 ◽  
pp. 01019
Author(s):  
Lev Zuev

The generality of localization of plastic deformation, which is observed at the stage of linear work hardening for HCP, BCC and FCC monoand polycrystals of pure metals and alloys, is considered. It was found previously that the motion rate of localized flow autowave is related to the reciprocal value of the work hardening coefficient by a linear law, which is universal in character. This is further substantiated by the results of the given study. The waves of plastic flow localization are found to have dispersion law. It has been established that in order to address the autowave of localized deformation, a quasi-particle may be introduced. The quasi-particle’s characteristics have been defined.


2001 ◽  
Vol 16 (8) ◽  
pp. 2283-2292 ◽  
Author(s):  
Masatoshi Futakawa ◽  
Takashi Wakui ◽  
Yuji Tanabe ◽  
Ikuo Ioka

This paper describes a novel technique for determining the constitutive equation of elastic–plastic materials by the indentation technique using plural indenters with different apex angles. Finite element method (FEM) analyses were carried out to evaluate the effects of yield stress, work hardening coefficient, work hardening exponent, and the apex angle of indenter on the load–depth curve obtained from the indentation test. As a result, the characterized curves describing the relationship among the yield stress, work hardening coefficient, and the work hardening exponent were established. Identification of the constants of a constitutive equation was made on the basis of the relationship between the characterized curves and the hardness given by the load–depth curve. This technique was validated through experiments on Inconel 600 and aluminum alloy. The determined constitutive equation was applied to the FEM analyses to simulate the deformation including necking behavior under uniaxial tension. The analytical results are in good agreement with experimental results.


2013 ◽  
Vol 6 (1) ◽  
pp. 1-9 ◽  
Author(s):  
P. R. Deepti ◽  
J. Shanti

Triglycine sulphate (TGS), an important ferroelectric material has been widely used in the fabrication of high sensitivity infrared detectors at room temperature. Single crystals of KDP doped TGS was grown by slow evaporation method at room temperature in this study. The grown crystal was characterized by UV-Vis spectroscopy, FTIR spectroscopy, powder X-ray diffraction studies, and ferroelectric studies. KDP doped TGS crystals were found to be highly transparent and full faced. The experimental results evidence the suitability of the grown crystal for optoelectronic applications.  Keywords: Crystal growth; KDP-doped TGS; Ferroelectric studies  © 2014 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.  doi: http://dx.doi.org/10.3329/jsr.v6i1.16584 J. Sci. Res. 6 (1), 1-9 (2014)


Author(s):  
Murat Bakirov ◽  
Sergei Chubarov ◽  
Igor Frolov ◽  
Joerg Gastrock

Ever-increasing requirements for reliability and safety of equipment in nuclear power plants (NPP) dictate a necessity to obtain reliable and validated information about the condition of materials in the most safety-relevant and economically vital systems structures and components (SSC). Thus it is a state of science and technology approach to use one method, one methodic and one methodology to facilitate these goals with the purpose of keeping NPPs operating safely by virtue of knowing the state of ageing they are in (with respect to design limits and margins). Method of the control/measurement/testing - how to conduct measurements; methodic - how to interpret the results of measurement; methodology - the program of the control/inspection and testing programmes: localities to conduct the tests, how often, and to follow evolution of test results with the aim of acting before a failure occurs. Such methodology should be based on the use of specimen-free nondestructive method of the inspection (control), which could be used successfully at all stages of life cycle of the equipment: manufacturing, construction, installation of NPP, operation and during the NPP operation through integration into the Plant Life Management (PLiM) programme [1]. It will facilitate a real picture of change (degradation) of a SSC material’s condition in the zones subjected to the harschest stressors (neutron irradiation, erosion-corrosion/flow, thermal fatigue, vibration etc). Currently, there are various approaches used in the world to follow NPP ageing degradation, but until now, no specific methodology is used that could supply all the necessary information [2]. Therefore, there is no way to use various results. Thanks to considerable advances over the last 20 years or so, the science of hardness testing offers an elegant, non-destructive way to obtain vital materials properties — even in-situ on operating SSC [3–6]. In particular, the material’s elastic-plastic condition may be measured, giving indications on tensile yield stress elevation due to hardening and also loss in ductility. The work-hardening index may be easily obtained, giving information on the ability of the material (e.g. pressure vessel steel and weld) to deform plastically without brittle fracture. Taking into account the experience of the Center of Material Science and Lifetime Management Ltd. (CMSLM Ltd.) in the use of methods of hardness testing for the inspection of the equipment of NPP of Russian manufacture in Russia, Germany, Czech, Slovakia, Bulgaria [7], and also similar successful works in this direction in USA (Oakridge) [8], to Czech (NRI Rez) and other countries, it can be seen that the most promising direction in the field of specimen-free inspection of mechanical properties by use of hardness and hardness-related characteristics is use of the kinetic indentation method (KIM, ABIT). This method is based on recording the process of elastoplastic deformation caused by the indentation of a ball indenter. This method allows one to obtain, besides hardness values, tensile properties, elongation, work hardening coefficient, true-stress/true strain diagrammes which normally required the destructive testing of small specimens. However, till now there is no universal method of interpreting the information obtained, although it is generally known that irradiation causes a loss in ductility and increase in hardness and lowering of the work-hardening coefficient. Thus, it is necessary to develop a uniform methodology of using KIM, ABIT with reference to the inspection of materials which will allow to unify the inspection of materials of various classes of the equipment of NPP over all stages of life cycle. With the purpose of introduction of such a methodology it is necessary to develop and realize the program in the frames of IAEA with the above name.


2015 ◽  
Vol 1086 ◽  
pp. 79-84 ◽  
Author(s):  
P. Malliga ◽  
A. Joseph Arul Pragasam

Single crystals of pure and thiourea substituted L-alanine single crystals were grown successfully by the solution method with slow evaporation technique at room temperature. The effect of dopant on crystal properties has been studied. The solubility of the grown samples was found at various temperatures. Structural characterization of the grown crystals was determined by the single crystal X-ray diffraction (XRD). EDAX studies indicate the presence of thiourea in the doped L-alanine crystals. The functional groups were identified by FTIR spectroscopy. The UV-Vis- NIR spectral studies were carried out to analyze the optical absorption of the grown crystals and found that the absorption is very low in the wavelength region 232-1000nm for both the samples. SEM studies explain the surface morphologies of the grown crystals. Improvement in the SHG efficiency was studied by the Kurtz and Perry method. Thermal analysis has been carried on the grown crystal. Keywords: NLO, XRD, EDAX, UV-Vis-NIR, SEM


2000 ◽  
Vol 653 ◽  
Author(s):  
Olivier Couteau ◽  
Corinne Charbonnier ◽  
Tomas Kruml ◽  
Jean-Luc Martin

AbstractRepeated stress-relaxation experiments are used to characterize the deformation parameters in 3 types of single crystals (Cu, Ni3Al and Ge) in which different dislocation mechanisms are known to operate. Mobile dislocation exhaustion rates and the amplitude of the yield point at reloading after stress-relaxation are measured. These two parameters are discussed in terms of the work-hardening coefficient in monotonic tests.


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