Sankaranarayanan–Ramasamy 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

Experimental and theoretical investigation on the SR method grown semi-organic Piperazinium Tetrachlorozincate Monohydrate (PTZM) single crystal for optoelectronic applications

Efficient semi organic nonlinear optical (NLO) Piperazinium Tetrachlorozincate monohydrate (PTZM) [C4H12N2][ZnCL4]·H2O single crystals have been grown by slow evaporation solution technique (SEST) and Sankaranarayanan-Ramasamy (SR) method using water as solvent. Single crystal X-ray diffraction (SXRD) analysis reveals the unit cell parameters of the grown crystal. The morphology of the grown crystal was identified by the single crystal XRD analysis. The electrical properties, dielectric constant, dielectric loss and piezoelectric (d33) coefficient were determined. The etch pit density of PTZM crystal has been calculated by using the chemical etching analysis. The laser damage threshold (LDT) analysis was investigated by Nd: YAG laser and the wavelength of laser is 1064 nm. The mechanical stability of the grown PTZM crystal was studied using Vickers microhardness measurement. Utilizing quantum chemical calculations, the PTZM compound is analyzed for vibrational properties, HOMO and LUMO characteristics, NBO interactions, and the determination of first-order hyperpolarizability. The nonlinear susceptibility and first-order hyperpolarizability results provide compelling evidence and affirm the PTZM molecule’s potential as a strong candidate for nonlinear optical (NLO) applications.

Comparative investigation on slow evaporation solution technique and Sankaranarayanan-Ramasamy (SR) method semi-organic Piperazinium Tetrachlorozincate Monohydrate (PTCZM) single crystal for optoelectronic applications

Comparative investigation on slow evaporation solution technique and Sankaranarayanan-Ramasamy (SR) method semi-organic Piperazinium Tetrachlorozincate Monohydrate (PTCZM) single crystal for optoelectronic applications

Structural, vibrational, optical and second harmonic generation studies of urea doped single KDP crystals grown by Sankaranarayanan–Ramasamy technique

Structural, vibrational, optical and second harmonic generation studies of urea doped single KDP crystals grown by Sankaranarayanan–Ramasamy technique

Sankaranarayanan-Ramasamy (SR) technique L- threonine lithium chloride single crystal: Unidirectional growth, optical and mechanical studies

L-Threonine Lithium Chloride (LTLC), an effective semi-organic NLO material, was successfully produced as a bulk single crystal using the Sankaranarayanan Ramasamy (SR) process. According to a study of a single crystal's X-ray diffraction, LTLC crystallises in an orthorhombic system with space group P212121. From the powder XRD method, unidirectional development along the plane (110) was established. The optical absorption spectra reveals that LTLC has a broad bandgap of 3.75 eV and is very transparent over the whole visible region. On the magnified crystal, photoconductivity measurements show positive photoconductivity. According to the photoluminescence investigation, LTLC emits green light with a wavelength of 535 nm. Vickers microhardness testing was done to determine the crystal's mechanical strength. At different temperatures and frequencies, the dielectric constant and dielectric loss were calculated. In addition to the density functional theory (DFT) calculations such as frontier molecular orbital’s (FMOs), analysis was carried out. Utilizing Kurtz's Nd:YAG Laser, powder testing is another method used to assess the produced crystal's SHG activity.

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.

A comparative study of 4-chloro 3-nitro benzophenone crystals grown by slow evaporation solution and Sankaranarayanan–Ramasamy methods

A comparative study of 4-chloro 3-nitro benzophenone crystals grown by slow evaporation solution and Sankaranarayanan–Ramasamy methods

A study of the phase transition by the electrical resistivity and photocurrent on TGS crystal grown using the unidirectional growth method of Sankaranarayanan–Ramasamy

A study of the phase transition by the electrical resistivity and photocurrent on TGS crystal grown using the unidirectional growth method of Sankaranarayanan–Ramasamy

Improvement of optical properties of KDP crystals by borax additive

KDP (Potassium dihydrogen phosphate, KH2PO4) single crystals were grown in Borax (Sodium tetraborate decahydrate, Na2B4O7·10H2O or Na2[B4O5(OH)4]·8H2O) added aqueous solutions by the slow cooling method and Sankaranarayanan-Ramasamy (SR) technique. The concentrations of Borax were 0.05, 0.1, 0.5, and 1 mol%. Impurities containing hydroxyl (-OH) groups such as Borax can increase the number of hydrogen bonds in KDP crystals, which plays a key role in governing the optical properties of KDP crystals. This comment was proved by the results of the measurements: Ultraviolet–visible (UV–Vis) spectroscopy, Raman spectroscopy, X-ray diffraction (XRD) analysis, and Second Harmonic Generation (SHG). Borax is an important candidate in the current research of impurity-doped KDP crystal for nonlinear optical applications.

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

Investigation on the bulk crystal growth, crystalline perfection, refractive index and piezoelectric properties of borate single crystals for piezoelectric and electro-optic applications

Low solubility potassium pentaborate tetrahydrate (KB5), ammonium pentaborate tetrahydrate (AB5) and mixed (KAB5) single crystals have been grown by the Sankaranarayanan-Ramasamy (SR) method. The crystal structures and space groups have been confirmed by powder XRD analysis. The direction of the grown crystal was confirmed by the back reflection X-ray Laue pattern. The crystalline perfection (CP) of the crystals have been evaluated using HRXRD studies. The transmittance spectra of the grown crystals were recorded by UV–Vis-NIR transmission studies showing that all the crystals have 90% transmittance in the entire visible region and found that the crystals' cut off wavelengths were below 200 nm. The optical studies such as refractive index (RI) and birefringence interferometry (BI) were reported. The RI for five different wavelengths of KB5, AB5 and KAB5 crystals were analyzed using the prism coupling method (PCM). Electromechanical behavior of the grown crystals was observed using piezoelectric coefficient (d33) measurement. Vickers Microhardness (VMH) measurement carried out at 30 °C shows increased hardness as the load increases.

FTIR spectral analysis of glycine doped ammonium dihydrogen phosphate (ADP) crystal

Ammonium Dihydrogen Phosphate crystals doped with Glycine (GADP) has been grown by slow evaporation method, Rotation method and Sankaranarayanan - Ramasamy (SR) methods with different molar concentration. The Fourier Transform Infra-Red (FTIR) studies have been investigated on the as grown GADP crystals. The FTIR spectrum shows the interaction between ADP and the dopant by the additional peaks which corresponds to the functional groups of Glycine. The standard spectrum statistics of FTIR confirms the presence of all the functional groups. The spectrum for ADP crystals doped with Glycine grown by Rotation and SR methods have similar peaks with slight variation as that of conventional slow evaporation method grown Glycine doped ADP crystals.

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.

TGS crystal growth below and above Curie temperature (Tc)

Ferroelectric triglycine sulphate (TGS) single crystals were grown by conventional slow cooling and unidirectional solution growth method below and above its Curie temperature (Tc). The evolution of morphology of TGS crystals during conventional growth method was imaged in an online and in-situ manner using laser shadowgraphy, and the growth rates of the crystals along a, b and c-axis were measured in both the temperature regimes. It was found that the growth rates of crystal grown above Tc was higher than that of the crystal grown below Tc. TGS crystals oriented along [010] polar direction and having large (010) habit face were successfully grown below and above its Curie temperature (Tc) by Sankaranarayanan-Ramasamy (SR) unidirectional solution growth method. Time-lapsed photographs of SR growth process were captured at regular interval of time, from where the growth rates of crystals along [010] direction was computed to be 1.5 and 2.2 mm/day for crystals grown below and above Tc respectively. The growth conditions were optimized and the dimension of the grown crystals were 60 mm length and 15 mm diameter for below Tc and 35 mm length and 15 mm diameter for above Tc. Using shadowgraphy, the buoyancy-driven convective patterns around the growing TGS crystals were imaged and the gradual buildup of this activity with the dimension of the crystal and time of the growth was investigated. Shadowgraphy was also used to map the evolution of morphology of TGS crystals growing below and above Tc, and growth rates along the three main crystallographic directions were computed. Mach-Zehnder interferometry was used to image development of concentration gradient in the crystallizer during growth.

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.

Growth of [010] oriented urea-doped triglycine sulphate (Ur-TGS) single crystals below and above Curie temperature (Tc) and comparative investigations of their physical properties

Optically transparent, urea (5 wt%)-doped triglycine sulphate (Ur-TGS) single crystals were grown along polar axis [010] by Sankaranarayanan–Ramasamy unidirectional solution growth method, below and above its Curie temperature Tc = 49.3 °C. Higher growth rate of 5 mm/day was obtained for Ur-TGS crystal grown above Tc. The phase of the grown crystals was confirmed by powder XRD. P–E hysteresis studies show well-saturated hysteresis loop for crystal grown below Tc, and the remnant polarization was 0.60 µC/cm2 with a coercive field of 1.5 kV/cm. The piezoelectric d33 coefficient for Ur-TGS crystal grown below and above Tc was 25 pC/N and 35 pC/N, indicating improved piezoelectric properties of the latter. Dielectric permittivity for Ur-TGS crystal grown above Tc was approximately 10 times higher as compared to the crystal grown below Tc. Improved Vickers microhardness and lower Meyer’s index (n) were observed for Ur-TGS crystal grown above Tc. The etch pit density (EPD) of Ur-TGS crystal grown below and above Tc was 1.8 and 1.1 × 102 dislocations/cm2, respectively, indicating that the quality of the crystals grown above Tc was better than the crystal grown below Tc. The optical transmittance of Ur-TGS crystal grown above Tc was slightly (~ 5%) more than that of crystal grown below Tc. Overall, it is concluded that the higher growth rate and improved physical properties of Ur-TGS crystal grown above its Curie temperature show its suitability for the ferroelectric device applications.