Ramasamy Method Research Articles

Development of high-quality and large-size 2-amino 4,6-dimethyl pyrimidine 4-nitrophenol single crystal by immersed Sankaranarayanan–Ramasamy (ISR) method

Development of high-quality and large-size 2-amino 4,6-dimethyl pyrimidine 4-nitrophenol single crystal by immersed Sankaranarayanan–Ramasamy (ISR) method

Study of the Crystalline Perfection, Homogeneity, Chemical Etching on the Surface, and Third‐Order Nonlinear Optical Properties of (1 1 0) Oriented Hydroxyethylammonium D‐Tartrate Monohydrate Single Crystal and Hirshfeld Surface Analysis

AbstractThe single crystal of hydroxyethylammonium D‐tartrate monohydrate (HEDT) is grown along the (1 1 0) plane using the Sankaranarayanan–Ramasamy method. The powder X‐ray diffraction and the high‐resolution X‐ray diffraction analyses are used to corroborate the growth plane and perfection of the crystallinity, respectively. The birefringence experiment has proven crystalline homogeneity and estimated birefringence value (Δn) is 0.109. The surface morphology of the grown crystal is examined by chemical etching analysis and irregular hillock patterns are found. The transmittance for the (1 1 0) plane of the HEDT is inspected by a UV‐Vis analysis. The second harmonic generation efficiency of the HEDT crystal is 1.7 times that of potassium dihydrogen phosphate (KDP). The third‐order nonlinear optical (TONLO) properties of the grown HEDT crystal are scrutinized by the Z‐scan experiment. The estimated TONLO susceptibility of HEDT crystal is 6.827 × 10−8 esu. The laser damage threshold value of HEDT is discovered to be 5.24 GW cm−2. The 3D Hirshfeld surface visualizes the interaction between HEDT molecules and analyzes the distance from the surface of the molecule to the farthest and the nearest atom. The important contributions of crystal packing are explored by 2D‐fingerprint plots.

Growth of large size Triphenylphosphine Oxide 4-Nitrophenol (TP4N) single crystal by Sankaranarayanan–Ramasamy (SR) method for third order nonlinear optical applications

The bulk size organic Triphenylphosphine Oxide 4-Nitrophenol (TP4N) single crystal was grown by Sankaranarayanan-Ramasamy (SR) method. Transparent, yellow color 〈011〉 oriented bulk size single crystal with 170 mm length and 15 mm diameter was grown by SR method. The various (hkl) planes of the SR-grown TP4N crystal were analyzed by powder X-ray diffraction (PXRD). The crystalline perfection of the SR grown TP4N single crystal was analyzed by high-resolution X-ray diffraction (HRXRD) measurement. The optical quality of SR-grown TP4N single crystal was analyzed by UV–Vis NIR. The dislocation density of SR grown TP4N crystal has been investigated by etching studies. The laser damage threshold (LDT) of the SR grown TP4N crystal was analyzed by Q-switched Nd: YAG laser of wavelength 532 nm. The optical homogeneity of TP4N was determined by the birefringence interferometry technique. The refractive index value of SR grown TP4N crystal was calculated by Brewster's angle measurement. The nonlinear refractive index (n2), absorption coefficient (β) and third-order nonlinear susceptibility (χ(3)) were studied using Z-scan technique.

Growth Aspect, Structural and Optical Properties of Unidirectional Growth of Potassium Hydrogen Maleate Single Crystal by Sankaranarayanan–Ramasamy (SR) Method

Growth Aspect, Structural and Optical Properties of Unidirectional Growth of Potassium Hydrogen Maleate Single Crystal by Sankaranarayanan–Ramasamy (SR) Method

Immersing ampoule Sankaranarayanan–Ramasamy (ISR) method: Unidirectional high-quality single crystal growth

The optically good quality organic 2-aminopyridinium 4-nitrophenolate 4-nitrophenol (2AP4N) single crystal (length 120 mm and diameter 15 mm) was grown by a novel Immersing ampoule Sankaranarayanan–Ramasamy (ISR) method. The water covered completely the ampoule containing growth solution in the unidirectional method for the first time in the literature. The ampoule was specially designed for the growth of good quality and bulk size unidirectional single crystals by slow cooling condition. The unwanted temperature gradient developed on the solution surface was completely avoided, hence the secondary nucleation developed on top of the ampoule is avoided. The growth apparatus and optimizations parameters have been made simpler compared to the conventional SR method. Growth direction parallel to the gravity direction can be easily achieved, hence slanted growth could be avoided within the ampoule and also linear transportation of embryos from solution to crystal-solution interface is achieved. The ISR method-grown single crystal was subjected to various characterizations. The optical behavior of the grown crystal was analyzed by UV–Vis NIR spectrophotometer. The optical homogeneities of the single crystal have been analyzed by birefringence measurement. The growth of 〈001〉 direction was confirmed by the PXRD analysis. The crystalline perfection of different growth portions (bottom, middle and top) was analyzed by HRXRD measurement. The full-width at half maximum (FWHM) values of various regions, indicate that the whole grown crystal has high crystalline perfection and is optically homogeneous. The new crystal growth ISR method has been introduced and also the various studies reveal that the ISR method grown single crystals are favorable for high performance optical device applications.

Investigation on unidirectionally grown < 010 > potassium acid phthalate single crystal by Sankaranarayanan–Ramasamy (SR) method for optical applications

Investigation on unidirectionally grown < 010 > potassium acid phthalate single crystal by Sankaranarayanan–Ramasamy (SR) method for optical applications

An Investigation on Thermophysical and Dielectric Properties of Ammonium Dihydrogen Phosphate Single Crystal for Opto-electronic Device Applications

Ammonium dihydrogen phosphate (ADP) crystal utilizes several applications such as Q-switching, electro-optical, and second harmonic generation in nonlinear optics. In the present article, a good-quality single crystal of ADP was grown via Sankaranarayanan–Ramasamy (SR) method for the dimension of 120 mm in length and 12 mm in diameter. The grown ADP crystal is used for diverse characterizations like FTIR spectral study, Vickers microhardness, second harmonic generation, photoluminescence, and chemical etching analysis. The photoacoustic spectroscopy analysis was used to study the thermal diffusivity of the sample. Thermal transport properties of the crystal are required for all types of heat transfer incidences and furthermore used in several applications like acousto-optical, Nd:YAG, and Nd:YLF lasers. A dielectric property was investigated for the grown crystal with dissimilar temperatures, and it was apt for electro-optical and Q-switching applications.

Determination of SHG deff by Maker fringes studies on unidirectional grown guanidinium chlorochromate single crystal for NLO device applications

Optically good-quality, organometallic bulk single crystal of guanidinium chlorochromate (GCC) was fruitfully grown by Sankaranarayanan–Ramasamy (SR) method. Translucent (− 1 − 1 2) aligned unidirectional bulk single crystals of diameter 20 mm and length maximum up to 48 mm were grown over the growth period of 23 days with growth rate of 1 mm/day by the SR method. Optical studies reveal very high transmission of the crystal along the growth axis. Microhardness measurement along the growth axis enounces high mechanical stability of the crystal. Laser damage threshold value of 1.11 GW/cm2 has been determined using Q-switched Nd:YAG laser radiation for GCC single crystal and reported for the first time. The second harmonic generation (SHG) of GCC crystal was investigated by the SHG Maker fringes technique. The refractive index and birefringence value of GCC crystal were found.

Effect of xylenol orange on the crystalline perfection, optical, piezoelectric and NLO behavior of unidirectionally grown imidazolium L-Tartrate single crystal

Pure and 0.1 mol% Xylenol orange (XO) doped Imidazolium L-tartrate (IMLT) nonlinear optical (NLO) single crystals were grown using Sankaranarayanan–Ramasamy (SR) method of uniaxial solution crystallization technique. The pure IMLT crystal is 100 mm in length and 15 mm in diameter. The doped IMLT crystal is 25 mm in length and 10 mm in diameter. UV–Vis-NIR spectrum shows that the pure and XO doped IMLT crystals' cut off wavelength is 235 nm. High-resolution X-ray diffraction (HRXRD) measurement and birefringence interferometry confirm that the SR method grown crystal has good crystalline perfection and optical homogeneity. The wavelength dependent refractive index and piezoelectric d33 coefficient were measured. The difference refractive index (Δn) of (100) plane in parallel and perpendicular directions shows a strong dependence on wavelength. The dielectric constant, hardness and SHG conversion efficiency were also increased as a result of XO dye doping in IMLT crystal.

Evaluation of Linear and Nonlinear Optical Properties of D−π–A Type 2-Amino-5-Nitropyridinium Dihydrogen Phosphate (2A5NPDP) Single Crystal Grown by the Modified Sankaranarayanan–Ramasamy (SR) Method for Terahertz Generation

We report the growth process and linear and nonlinear optical characterization of high quality improvised semiorganic 2A5NPDP single crystal using the modified SR method for the first time. The maj...

Unidirectional seeded growth of l-Glutamic acid hydrobromide single crystal and its characterization

ABSTRACTl-Glutamic acid hydrobromide single crystals were grown by Sankaranarayanan–Ramasamy (SR) method for the first time. Seed crystals were prepared from the solvent evaporation technique. Using single-crystal X-ray diffraction (XRD) analysis, the crystal system and the cell parameters were determined. The TG/DTA analysis shows that the crystal is stable up to 200°C and further increase of temperature decomposition was observed. The crystal has a sharp cutoff around 230 nm and is transparent in the UV region. High-resolution XRD curve of 22 arc s FWHM shows the excellent crystallinity nature. Further, the Vicker's hardness test proved that the hardness of the crystal grown using SR method is found to be higher than the crystal grown with the conventional solution grown technique. Etching studies were performed to find the growth pattern and the results are presented and discussed in detail.

Modification of optical properties of ammonium dihydrogen phosphate crystal by employing shock waves

We describe the investigation into tailoring the optical properties of ammonium dihydrogen phosphate (ADP) crystal by the influence of mild shock waves (Mach number 1.7) produced by a shock tube. An ADP crystal was grown by employing the Sankaranarayana–Ramasamy method with (101) orientation. The test crystal was subjected to different numbers of shock pulses such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, and 13, respectively. Pre- and post-shock wave-loaded test crystals were experimented with a ultraviolet-visible spectrometer for recording the optical transmission. From the observed results, it is known that, on increasing shock pulses, optical transmission is enhanced from 55% to 66% in such a way that optimization is attained. Thereafter, it reduces to 47% by further increasing the number of applied shock waves. Following the optical transmission, optical constants such as extinction coefficient, optical density, skin depth, real and imaginary parts of the dielectric constant, optical conductivity, and electrical conductivity are also greatly altered if the ADP crystal is exposed to shock pulses. From this experiment, an alternative way to boost the optical properties of an ADP crystal without modifying the original crystal system and without adding any dopants is proposed.

An investigation on optical, mechanical and thermal properties of nickel sulphate hexahydrate single crystal—a UV band pass filter

Nickel sulphate hexahydrate (NSH) crystal is known to be an excellent material for UV light band-pass filter applications. In this research work, good quality and enhanced size of NSH single crystal has been effectively grown by implementing Sankaranarayanan—Ramasamy (SR) method. After a prolonged period of 185 days, a fine quality of transparent as well as improved size single crystal of NSH with dimension 220 mm in length and 12 mm in diameter has been successfully harvested. The grown crystal has been subjected to various characterizations as that of single crystal x-ray analysis to confirm the crystal system with unit cell parameters, UV–Vis analysis to know the transmission spectrum, FTIR spectral analysis to find out the functional groups and photoluminescence study to affirm the green emission of the crystal. NSH crystal falls into the category of soft material as identified by microhardness study and etching study confirms that it has good quality as the surfaces are almost free of defects. Photoacoustic spectroscopy has been utilized to find the thermophysical parameters. The resultant value of thermal diffusivity is compared with few other familiar nonlinear optical materials such that it is asserted by the observed superior value of NSH single crystal that it is an added advantage for band-pass filter and harmonic generation applications.

Growth of high-quality organic single crystal of 2-aminopyridinium 4-nitrophenolate 4-nitrophenol (2AP4N) by a novel Rotational Sankaranarayanan–Ramasamy (RSR) method

The good quality 2-aminopyridinium 4-nitrophenolate 4-nitrophenol (2AP4N) single crystals have been grown by (i) Sankaranarayanan–Ramasamy (SR) method and (ii) Rotational Sankaranarayanan–Ramasamy (RSR) method. The effect of rotation on unidirectional crystal growth method (RSR) has been reported for the first time. The apparatus was specially designed and developed for the growth of high-quality crystals by slow cooling under rotational conditions. The high-quality crystals have been achieved under forced convection and the quality of the crystal is compared to the crystals grown under free convection conditions. The crystal structure was analyzed by single crystal X-ray diffraction (SXRD) measurement. The grown crystal was subjected to the powder X-ray diffraction (PXRD) analysis to confirm the growth direction along (0 0 1) plane. The optical quality of the grown crystals has been analyzed by UV–Vis NIR spectrophotometer. It confirms that the grown crystal is highly transparent in the visible and near IR region. The photoluminescence behaviour was recorded in the wavelength region between 450 and 700 nm. It confirms that the grown crystal has emission at 500 nm. The electro-optical properties of the grown crystal were analyzed by photoconductivity measurement and it has positive photoconductivity nature. The grown crystal has less dislocation densities as confirmed by chemical etching analysis. The mechanical strength was investigated by Vickers microhardness tester. The frequency dependent dielectric properties of the crystals were investigated. The laser damage threshold (LDT) was measured for both SR and RSR method grown crystals. The full-width at half maximum (FWHM) of high-resolution X-ray diffraction (HRXRD) curves indicate that the grown crystal has high crystalline perfection. The results obtained from the SR and RSR method grown 2AP4N crystals were compared. The RSR method grown crystal has higher optical transparency, higher photoluminescence, higher photoconductivity, higher mechanical strength, higher laser damage threshold, higher crystalline perfection, less dislocation density, low dielectric loss and low full with at half maximum (FWHM). The second harmonic generation (SHG) of 2AP4N was analyzed by Kurtz-Perry powder technique. The SHG efficiency was found to be 4.5 times that of reference KDP material. The above studies reveal that the RSR method grown crystals are more useful for device applications.

Growth, optical, mechanical and thermal behavior of unidirectionally grown L-Glutaminium p-Toluenesulfonate crystal

Organic crystal of L-Glutaminium p-Toluenesulfonate (LGPT) was grown in unidirectional by Sankaranarayanan and Ramasamy (SR) method. The grown crystal belongs to monoclinic crystal system with noncentrosymmetric space group P21. High resolution XRD confirms crystalline perfection of the grown crystal. Optical transmission shows that unidirectional grown crystal has higher transmittance and the lower cut-off wavelength is 290 nm. The emission wavelength of grown crystal is 410 nm and emission region is confirmed by luminescence spectra. The laser damage threshold value of unidirectional crystal has increased by 0.3 GW cm−2. The grown LGPT crystals belong to hard material category and it confirms the normal indentation size effect. The grown LGPT crystal is thermally stable upto 165 °C and decomposition of the molecules were elucidated by using TGA and DSC. Powder second harmonic generation measurement confirms the efficiency of the grown LGPT crystal is 0.8 times that of KDP.

Shock wave induced enhancement of optical properties of benzil crystal

In this article, we present the results of the experimental work on the impact of shock waves on optical properties of benzyl crystalline material. Test material of benzil crystal is grown along [100] plane by Sankaranarayana — Ramasamy method. In the present work, the functional shock waves of Mach number 1.7 are generated from pressure driven shock tube. The optical properties of test material are investigated by UV-Visible spectrometer over the range between 200 and 800 nm. The observed results show that the intensity of the absorption spectrum is inversely proportional to the number of exposed shock waves. The direct and indirect optical band gap energy (Eg) and Urbach tail energy (Ug) are determined from the optical absorption spectrum for pre and post shock wave loaded condition and found that shock wave loaded test crystal has high band gap energy. The optical constants namely extinction coefficient, real and imaginary parts of the dielectric constant, skin depth, optical density, optical conductivity and electrical conductivity are investigated and the obtained results are compared with post shock wave loaded benzil crystal with the incident light possessing wavelength at 700 nm. The results are found to be very impressive for the shock wave recovery experiments that are to be clearly discussed.

Some structural, linear and nonlinear optical characteristics of single KDP crystals influenced by EDTA additive

Single Potassium Dihydrogen Phosphates (KDP) crystals were successfully grown in pure and 1 mol% Ethylenediaminetetraacetic acid disodium salt (EDTA) added KDP solutions by Sankaranarayanan–Ramasamy method. Their growth was oriented in type I phase-matching direction which is one of two conditions of maximum second harmonic generation efficiency. The elemental compositions of the crystals were determined by EDX analysis. The UV–Vis spectroscopy, FT-IR analysis, X-Ray diffraction, and second harmonic generation studies have been carried out in order to assess the influence of EDTA additive on quality of KDP crystal. EDTA can improve the structural perfection and optical characteristics of the crystal. Especially, this additive helps increase second harmonic generation efficiency of KDP crystal, which is very useful for frequency doublers.

Vacuum‐Assisted Technique to Modify the SR Method for Unidirectional Crystal Growth

AbstractThe design and fabrication of a vacuum‐assisted Sankaranarayanan–Ramasamy (SR) method is reported by making modifications in the original SR setup for the growth of bulk single crystals with selective orientation at room temperature using volatile solvents. Utilizing this technique, the growth of bulk‐sized and technologically important single crystals, such as KDP, TGS, ADP, and benzophenone, is demonstrated. The powder XRD patterns of the grown crystals are obtained so as to confirm the growth plane of each crystal. UV–visible spectra show good transparency in the entire visible region for the grown crystals. The crystalline perfection of the grown crystals is analyzed using HRXRD. This handy and cost‐effective technique will pave the way for the growth of single crystals satisfying the requirements of the photonic industry.

Growth and Characterization of Triglycine Sulphate Single Crystal by Sankaranaryanan–Ramasamy Method

Transparent single crystal of dimension 10 x 1 x 1 cm3 has been successfully grown from Sankaranarayanan–Ramasamy (SR) method. The grown crystal was subjected to Optical Transmittance studies using UV-Vis-NIR spectrum. The presence of various functional groups and the vibrational structure of the compound was elucidated from Fourier transform infrared analysis. The other possible vibrations have also been identified through Raman stud

Investigation of unidirectional growth and characterization of nonlinear optical L-alaninium p-toluenesulfonate crystal

An aminoacid nonlinear optical crystal of L-alaninium p-toluenesulfonate (LAPT) was grown by Sankaranarayanan and Ramasamy (SR) method. The seed crystal of LAPT was grown with the help of a conventional solution method. The size of the grown crystal is 50 mm length and 20 mm diameter for (0 1 0) plane. The solubility of LAPT was determined in deionized water. The grown LAPT crystal belongs to the orthorhombic crystal system with noncentrosymmetric space group P212121. The morphology of the grown LAPT crystal reveals a hexagonal shape with six facet. The lower cut-off wavelength of the grown crystal is found to be 285 nm. Optical transmittance of the crystal grown by SR method is increased by 20%, when compared with the conventionally grown crystal. The LDT value of the SR-grown LAPT crystal has increased by 0.57 GW cm−2, compared with LAPT crystal grown by conventional method. The emission spectra of the grown crystal was analysed by photoluminescence analysis. The mechanical strength of the grown LAPT crystal was analysed by using Vickers hardness test, and the work hardening coefficient (n) of the LAPT crystal grown by SR method is found to be 2.20. The second harmonic generation efficiency of the LAPT crystal is 2.1 times that of KDP.