Pure KDP Crystals Research Articles

Crystallization of KDP in the presence of 4-nitro benzoic acid, L-ornithine hydrochloride and terephthalic acid

The present study is to investigate the optical, thermal and SHG properties of grown potassium dihydrogen phosphate (KDP) crystals using slow evaporation method in the presence of 4-nitro benzoic acid, l-Ornithine Hydrochloride and Terephthalic acid. Powder crystal XRD studies confirm their structure as that of KDP. The presence of functional groups has been tested and confirmed by FTIR. UV–visible spectral analysis - Differential Reflectance Studies (DRS) is used to examine the optical properties of pure and doped KDP crystals within the wavelength range of 200–800 nm and also evaluate the band gap, refractive index, extinction coefficient and optical conductivity of the grown crystals. Thermal properties of grown crystal are analysed by Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC). Second harmonic generation test is carried out for the grown crystals to analyse nonlinear optical (NLO) properties.

Effect of Organic Entities on the Performance of Potassium Dihydrogen Phosphate (KDP) Crystals

The 0.5mol l-cystine and 2mol oxalic acid doped in potassium dihydrogen phosphate crystals have been developed by slow evaporation method at room temperature. The structural properties of the grown crystal were analyzed by powder X-ray diffraction technique. The functional groups of grown crystals were successfully identified using FTIR spectral analysis. The optical transparency of the grown crystals is examined in the range of 200-900 nm using UV-visible studies. The optical transmittance is found to be 87 % of the grown crystal. The energy band gap (Eg) of the grown crystal was calculated at 3 eV. The Kurtz- Perry test has been employed to determine the SHG efficiency and the SHG efficiency of the grown crystal was 0.5 % of pure KDP crystal tested by Kurtz-Perry powder technique.

Enhanced Mechanical, Thermal, Surface, Self-Defocusing, Electro-Optic and Photoelastic Characteristics of Doped Potassium Dihydrogen Phosphate Solitary Crystals for Optoelectronic Applications

Potassium dihydrogen phosphate (KDP) is an effective NLO substance. Much research has been concentrated on KDP crystals to increase the effectiveness of KDP's nonlinear optical property. The effectiveness of laser radiation conversion can be increased by altering its expansion. The excellent molecular chirality of organic acids is employed to improve the properties of KDP. Our main objective in this study was to describe the studies on the mechanical, thermal, surface, antibacterial, self-defocusing, and electro-optic properties of doped potassium dihydrogen phosphate solitary crystals for optical, electronic, and biological applications. The effect of itaconic acid (ITA) at concentrations ranging from 1, 3, and 5 mol% on the thermal, SEM, microhardness behaviors, NLO, antibacterial properties, and half-wave voltage of KDP (potassium dihydrogen phosphate) single crystals grown by the slow cooling technique. The existence of dopants was proved with energy-dispersive spectrometry. The mechanical properties of various temperatures for undoped and doped-KDP crystals with rising dopant combinations have been prepared, and the hardness was expanded due to doping. In contrast to several potentially dangerous microorganisms like Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli, the produced crystals were exposed to antibiotic activity. The superiority of the fully-fledged crystal is determined by the etching studies. Using the Z-scan method, the good third-order nonlinear response for different planes (2 0 0), (2 1 1), and (1 1 2) of the ITA-doped KDP crystal sample was determined. Half-wave voltage may be discovered in the crystal produced via electro-optic examination. The Z-scan analysis of pure and ITA-doped KDP crystals for different planes reveals good self-defocussing and NLO responses. The electro-optic experiment generated a significant and consistent half-wave voltage. The photoelastic behavior of KDP crystals with ITA as a variable birefringent compensator has been investigated.

Influence of tyrosine, glutamic acid and tryptophan amino acids on optical and thermal properties of KH2PO4 crystal

The present study aims to report the influence of Tyrosine, Glutamic acid and Tryptophan amino acids on optical and thermal properties of potassium dihydrogen phosphate (KDP) by growing single crystals, through slow evaporation method. Powder crystal XRD studies confirm their structure as that of KDP. The grown crystals have been tested by FTIR to confirm presence of functional groups. The enhancement of optical properties of pure KH2PO4 due to doping with Tyrosine, Glutamic acid and Tryptophan has been precisely examined by UV–visible spectral analysis within the wavelength range of 200–800 nm. UV–visible spectral analysis is also used to evaluate the band gap, refractive index, extinction coefficient, optical conductivity and electrical conductivity of pure and doped KDP crystals. Thermal properties of grown crystal are analysed by Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC).

Doped potassium dihydrogen phosphate single crystals with enhanced second-harmonic generation efficiency: an investigation of phase purity, nonlinear, piezoelectric, optical, and crystalline qualities

We investigated the impact of itaconic acid (ITA) on potassium dihydrogen phosphate (KDP) aimed at concentrations of 1, 3, and 5 mol % on Single Crystal x-ray Diffraction, Fourier Transform Infra-Red, absorption of optical charm, Powder XRD, improved second Harmonic Generation competency, and third order non-Linearity of fully grown solitary crystals formed by slow cooling (Low Temperature Solution Growth). The crystals were crushed into a powder with micron-sized crystals for x-ray diffraction research. The Powder XRD spectrum of different ITA doped KDP concentrations showed fewer peaks with higher intensities than pure KDP crystals. Doping in the KDP crystal matrix accelerate growth in the [200] plane. Despite vibration assignment modes of ITA doped KDP, the FT-IR spectrum shows doping materials in KDP crystalline media. ITA doped KDP showed 90% optical transmission in UV–vis-NIR spectroscopy, whereas pure KDP possessed 60%. The dielectric investigation found that doped KDP crystals had lower dielectric loss and greater dielectric constants than pure counterparts. In pure and doped crystals, piezoelectric effects and second harmonics are premeditated. Using the Z scan approach, we were able to assess the third order nonlinear optical behaviour of pure crystal samples as well as the effects of self-defocusing caused by doping of ITA in KDP. ITA doping contributes to the growth, nucleation, and induction period. Doping concentration initially accelerated growth. Photoluminescence study shows that fully formed crystals have fewer defects. High Resolution XRD study determined crystal quality.

Synthesize and analyze pureandmyrtaceaedopedkh2po4 crystals

Slow evaporation method at constant temperature was used to generate optically better-quality clove and pure doped Potassium Di-hydrogen Phosphate crystals, which were then characterized. If the optimum conditions are adequately attained, the slow evaporation method can be used to produce crystals with low solubility. FTIR spectra are used to assess the reality of crystal efficient groups qualitatively. To investigate the dopants effect on the ideal appearances of Potassium Di-hydrogen Phosphate, an X-ray diffraction investigation was carried out. The tetragonal design of KDP and incapacitated crystals was discovered via powdered X-ray diffraction. The lattice parameter values were determined using X-ray diffraction on a single crystal. UV-Visible spectroscopy was used to examine the generated clove doped (1:1) KDP crystals. The TG and DTA analysis were utilized to examine the constancy and breakdown of unpolluted and clove doped KDP crystals. ND-YAG laser was utilized to notice the SHG. Clove doped KDP crystals outperformed pure KDP crystals in terms of relative generation of second harmonics productivity. The effect of dopants on the exterior morphology of KDP crystals was investigated using a scanning electron microscope (SEM). EDAX was utilized to have a better understanding of the elements found in crystals.

Effect of some hydroxyl additives on the growth and optical properties of KDP crystals

Potassium dihydrogen phosphate (KDP) single crystal was doped with disodium tetraborate decahydrate (or borax), L-alanine, and disodium ethylenediaminetetraacetate (or disodium EDTA) with 0.05 mol%, 9 mol%, and 2 mol% concentration in the aqueous solution, respectively. These crystals were fabricated by the temperature reduction method incorporating the Sankaranarayanan-Ramasamy technique and were grown onto seed crystals that were inclined at the type I phase-matching angle to the vertical. Each doped KDP single crystal rod was cut into three parts: the bottom, the middle, and the top, which were related to the fabrication temperature range of 50–40 °C, 40–30 °C, and 30–20 °C, respectively. The effect of the additives on the growth and optical properties of KDP crystals was evaluated through Ultraviolet–Visible spectroscopy, Raman spectroscopy, X-Ray Diffraction analysis, Energy-Dispersive X-ray spectroscopy, and Second Harmonic Generation measurement. The hydroxyl impurities have improved the optical properties of KDP crystals by contributing more hydrogen bonds to the KDP lattice. The doped KDP crystals increased SHG efficiency by 1.19 to 2.36 times compared with pure KDP crystals.

Microhardness and SHG efficiency of pure and picric acid-added KDP crystals

Pure and picric acid-added KDP (potassium dihydrogen phosphate) crystals are grown by slow evaporation technique from aqueous solution. Unit cell parameters for pure and doped KDP crystals were measured from single-crystal X-ray diffraction studies. Vickers and Knoop microhardness studies were carried out on the grown crystals over a load range of 0.1 to 0.5 N. The microhardness decreases with load P, i.e., normal indentation size effect (ISE), and from Meyers index it is shown that grown crystals falls in to hard material category. Mechanical properties, such as Young’s modulus, yield strength, elastic stiffness constant, were calculated for pure and doped KDP crystals. Hardness anisotropy has been observed in accordance with the orientation of the crystal. Etching studies were carried out using aqueous solution as an etchant. Improved second-harmonic generation efficiency is observed for doped KDP crystals in comparison to pure KDP crystals.

Influence of l-Phenylalanine doping on potassium dihydrogen phosphate: crystal growth, structural, optical and mechanical traits

Potassium dihydrogen phosphate (KH2PO4; KDP) is a well known nonlinear optical (NLO) material for optoelectronic, laser technology and fiber optical communication device applications. In a view to yeild better device properties, l-Phenylalanine (l-Phe) aminoacid doped KDP (LKDP) crystals with different dopant concentrations (0.5 mol%, 1 mol% and 2 mol %) were grown by slow evaporation solution technique (SEST). The grown crystals were powdered of micron size crystallites and subjected to powder X-ray diffraction (PXRD). In PXRD spectra, a few peaks with increasing intensity were observed in LKDP crystals when compared to pure KDP, revealing the effect of incorporation of dopants in the crystalline matrix of KDP and the enhancement of growth rate along [100] direction. FT-IR spectrum confirms the incorparation of dopant in KDP crystalline matrix with the presence of different vibrational modes of assignments belongs to L-Phe. To study the crystalline perfection of pure and doped crystals, the high-resolution X-ray diffraction (HRXRD) was employed and the crystalline perfection was found to be reasonably good with relatively low values of FWHM. UV–Vis-NIR spectroscopy results show significant increase in optical transmission up to ~ 80% from ~ 60% (pure KDP) in the entire visible spectrum of l-Phe doped KDP at low doping concentration. However, it was decreased to ~ 70% when we increase the dopant concentration by 2 mol% and suggests that if we increase the dopant (l-Phe) concentration above an optimal value in KDP, the transmission decreases. The Photoluminescence (PL) spectrum reveals high crystalline perfection at low concentration of dopants as observed by the sharp peaks. The weak green emission peak for sample with higher dopant concentrations indicates the segregation of doped molecules at the structural grain boundaries as observed in the HRXRD studies. The mechanical strength of pure and doped KDP crystals with increasing dopant concentration has been studied and found that the hardness was increased slightly due to doping. The powdered sample of micron size particle made from as grown crystals were subjected to Kurtz powder technique to observe the relative second harmonic generation (SHG) efficiency in comparison with the pure KDP. These results reveal significant enhancement of SHG efficiency with increasing doping concentration up to 2 mol% in KDP crystals which is 1.31 times to that of pure KDP.

Growth, ultraviolet‐visible, vibrational, photoluminescence and second harmonic generation studies of Amaranth and EDTA co‐doped KDP crystals

KDP (Potassium dihydrogen phosphate) single crystals were grown from Amaranth dye and EDTA (Ethylenediaminetetraacetic acid disodium salt) mixed KDP solutions by the temperature lowering method and Sankaranarayanan-Ramasamy technique. The molar concentration of EDTA in the solutions was 1 mol%. The Amaranth concentrations were 0.001, 0.005, 0.01, 0.03 and 0.05 mol%. The growth of KDP crystals was oriented in type I and type II phase-matching directions which bring maximum second harmonic generation (SHG) efficiency to the crystals. Optical properties of Amaranth and EDTA co-doped KDP crystals (KAE) were investigated by Ultraviolet-Visible (UV-Vis) spectroscopy, FT-Raman spectroscopy, and photoluminescence. SHG efficiency of the crystals was measured by shining 1064 nm Nd:YAG laser directly into them and receiving output signals. The most important result in the study showed that KAE crystals had SHG efficiency of 1.7 and 2.4 times higher than EDTA doped KDP crystal (KE) and pure KDP crystal respectively. Then second-order nonlinear optical coefficients of these crystals were calculated. The simultaneous doping of two organic substances into KDP crystals has further enhanced their nonlinear optical characteristics.

Shock wave-induced optical band gap engineering on pure and dye-doped potassium dihydrogen phosphate crystals

At this point in time, there are only a few studies available which deal with the investigation on the effect of shock waves in structural, electrical, thermal, and optical properties of potassium dihydrogen phosphate (KDP) crystal that has been analyzed systematically in the previous publications (Sivakumar et al. in Opt Laser Technol 111:284, 2019; Sivakumar et al. in J Eelectron Mater 47:4831, 2018; Sivakumar et al. in Mater Res Express 6:086303, 2019; Sivakumar et al. in J Electron Mater 48:7868, 2019; Sivakumar et al. in Z. Kristallogr Cryst Mater, 2020, https://doi.org/10.1515/zrki-2020-0017 ). In this study, the prime interest is to explore the band gap engineering of pure and dye-doped KDP (methylene blue and rhodamine B) crystals by shock waves which would enable to get the deep insight so that better understanding of the relation between shock wave and optical physics could be arrived at and it would pave the way to get acquainted with more knowledge of the material itself. Optical band gap energies are calculated from Tauc plot relations and it is observed that the values of band gap energies are reduced with respect to number of shock pulses for all the test crystals. The reduction of band gap energy is due to the formation of surface defects and oxygen vacancies by the impact of shock waves and this effect is called as Franz–Keldysh effect (Strain Lattice effect). Among the three crystals, RB + KDP crystal is found to be the best such that it could be tuned for the range of band gap energy from 4.89 to 3.3 eV as compared to the other two crystals. Hence, an alternate method is proposed to understand band gap engineering of non-linear optical materials which are suitable for photonic applications.

Shock wave induced defect engineering on structural and optical properties of pure and dye doped potassium dihydrogen phosphate crystals

Abstract Based on the importance of the shock recovery experiments, the authors report the structural and optical properties of pure and 0.001 M dye-doped potassium dihydrogen phosphate (KDP) crystals for virgin and shock wave loaded samples. Rhodamine B and Methylene blue dyes are selected as dopants to be doped with KDP crystal for the present investigation. The test crystals of pure and doped KDP crystals are grown by slow evaporation technique and cut and polished crystals of (200) face are used for the present investigation. Table-top pressure driven shock tube is utilized for the shock wave generation and the used functional Mach number is 1.7. Virgin and shock wave loaded test crystals’ surface morphology, structural properties and optical transmissions are observed using optical microscope, powder X-ray diffractometer and UV-Visible spectrometer, respectively. Crystalline nature and optical transmission of pure and doped KDP crystals are found to have reduced by the impact of shock waves. It occurs due to the enhancement of defect concentration on the surface of the test crystals. From the observed results, we assert that the pure KDP crystal is relatively more stable to shock wave induced damage compared to doped KDP crystals as reflected by structural and optical studies.

Co-doping effect of Amaranth and EDTA on bulk growth, optical, structural properties and second harmonic generation of KDP crystals grown by Sankaranarayanan-Ramasamy (SR) technique

KDP (Potassium dihydrogen phosphate) single crystals co-doped with Amaranth dye and EDTA (Ethylenediaminetetraacetic acid disodium salt) with concentrations of 0.005 mol% and 1 mol% respectively in the solution were grown from seeds by the method of temperature reduction and Sankaranarayanan-Ramasamy (SR) technique. The seeds were mounted vertically and in a direction of 59° from the vertical. The latter orientation of the seed made second harmonic generation (SHG) efficiency of KDP crystal with the 1064 nm laser reach its maximum value. Bulk growth, optical, and structural properties of the crystals were assessed by UV–Vis spectroscopy, X-ray diffraction (XRD) analysis, and photoluminescence. The elemental composition of crystals was also determined by Energy-dispersive X-ray (EDX) spectroscopy. Amaranth and EDTA additives have improved the SHG performance of pure KDP crystals by up to 168%, which probably could not be achieved by doping either with Amaranth or EDTA. Finally, three different parts of the crystal rods grown by SR technique were not homogeneous in the optical, structural properties and the degree of being dyed.

Effect of sunset yellow dye on morphological, optical, dielectric, thermal and mechanical properties of KDP crystal

Herein, we describe the growth and morphology of well-defined dyed crystals of KH2PO4 (potassium dihydrogen orthophosphate; KDP) containing organic azo (sunset yellow; SSY) dye in the {1 0 1} & {0 0 1} pyramidal growth sectors. An understanding on selective dye inclusion in various growth sector of host crystal is proposed, which will help in designing novel tailor-made dyed photonic crystals. The structural analysis and the identification of various functional groups present in as grown KDP crystals were carried out using powder XRD, FTIR and Raman studies. Solid state transmittance spectra for dyed KDP crystals displayed three absorption peaks at 230 nm, 311 nm and 477 nm, which were blue shifted for SSY dye in KDP crystal relative to neutral aqueous solution of SSY dye. These blue shifts in the absorption maxima confirm the successful incorporation of sunset yellow dye into the pyramidal growth sectors of dyed KDP crystals. The band around 409 nm in the photoluminescence emission spectrum indicates a violet emission. SSY dye doped KDP crystals showed enhanced dielectric properties and thermal stability as compared to pure KDP crystal. The mechanical strength of the KDP crystals estimated using Vickers microhardness test was found to decrease with the increase in SSY dye doping.

Effects of dyes in the growth, optical, mechanical and dielectric properties of KDP crystals

One among the prominent single crystal potassium dihydrogen phosphate (KDP) was grown by slow evaporation solution technique and also doped with three organic dyes like Alizarin, Congo red and Evans blue. The cell parameters of the pure and doped KDP crystals were found using powder x-ray diffraction. The optical behavior of the pure and doped KDP crystals was analyzed through the UV–Visible absorption spectrum. The functional group analysis of the grown crystals was done using FT-IR spectral study. The emission characteristics of the pure and doped KDP were found using photoluminescence study which results in multicolored emission spectra. The second harmonic generation of the pure and doped KDP crystals shows better frequency conversion property of the crystals. The laser damage threshold (LDT) study was done for all the grown crystals and the results were compared. The growth pattern of the pure and dye doped KDP crystals were examined using etching analysis. The mechanical stability of the grown crystals was determined using Vicker’s microhardness study. The dielectric property of pure and dye doped KDP crystals are carried out at room temperature for different frequencies.

Inclusion of an anionic dye in the molecular structure of potassium dihydrogen phosphate crystal for SSDL applications

Single crystals of pure potassium dihydrogen phosphate (KDP) and Reactive Orange 16 or Remazol Brilliant Orange dye-doped (0.1, 0.2 and 0.3 mol%) KDP single crystals were grown by slow evaporation method with the vision to improve the properties of pure KDP crystal. Enhanced dielectric, optical, thermal and NLO properties have been achieved by dye doping. The crystallinity and phase purity of the grown crystals were analysed by PXRD. The identification of various functional groups and dye incorporation in the grown crystals was confirmed qualitatively by FTIR analysis. The linear optical study on pure and dye-doped crystals was carried out using UV–Vis–NIR spectroscopy. The optical band gap, extinction coefficient, refractive index and optical conductivity were calculated using the transmittance spectra for all the samples. The thermal stability and the decomposition temperature were found to increase with the concentration of the dopant. This indicates the high quality of the crystal as well as its perfection. The SHG efficiency measurements were taken for the grown crystals and found that the SHG efficiency increases with doping concentration. The enhanced optical constants, thermal stability and second harmonic generation ability confirm the suitability of the grown crystals for solid-state laser materials.

Incorporation of CdSe quantum dots (QDs) in KH2PO4 (KDP) crystalline host: Processes of elaboration and characterization

The aim of this work is to survey experimentally the effect of doping CdSe quantum dots (QDs) on structural and optical properties of Di-hydrogen phosphate KH2PO4 (KDP) single crystal, where we expose a simple and reproduced technic to obtain KDP:CdSe single crystal starting from aqueous solution phase. In order to characterize the samples comfortably, the obtained crystals were cleaved into pellets with suitable size each surface being parallel to the faces (100). The XRD results denote that the CdSe QDs inside KDP single crystal have only one preferred direction (110) and the estimated size as derived from Sheere’s formula proved the nano-regime of guest material. On the other side, UV–vis absorption spectrums appear that a pure KDP crystal has transparence property in the visible range with a large window where Eg (KDP) ≈ 7.17 eV. However, KDP:CdSe sample exhibits two bands located at 425 nm and 625 nm attributed to the transition band to band and excitonic, respectively. As an accordance result, photoluminescence (PL) measurements indicate that the band gap of CdSe QDs inside KDP single crystal appears a significant amount of blue-shift (ΔEg = 0.284 eV) due to well recognized quantum confinement effect exerted by the CdSe QDs.

Vickers Microhardness Studies of Pure and Amino Acids Doped Potassium Dihydrogen Phosphate Crystals

Vickers microhardness study was carried out to understand the mechanical behaviour of pure and different amino acids (L-arginine, L-lysine, L-alanine) doped potassium dihydrogen phosphate (KDP) single crystals grown by slow solvent evaporation technique. Indentations were made on smooth {100} plane of pure and different amino acid doped crystals for loads varying from 0.298 N to 0.98 N. Vickers microhardness decreased as doping level of amino acid was increased. Indentation size effect (ISE), Kick's law, Hays and Kendall's law and Proportion specimen resistance (PSR) model were verified for pure and different amino acids doped crystals. The values of the load independent hardness and Newtonian pressure were higher in pure KDP crystals than the amino acids doped KDP crystals. It was found that as doping concentration of amino acids increased the load independent hardness and Newtonian pressure decreased. The results indicated that the doping of amino acids made KDP crystals softer.

Dielectric Constant Measurements of Pure and Nickel Sulphate Doped KDP Crystals grown by Gel Medium

Dielectric Constant Measurements of Pure and Nickel Sulphate Doped KDP Crystals grown by Gel Medium

Doping effect of carboxylic acids on optical, electrical, mechanical and thermal traits of KDP crystal

Single crystals of maleic acid (MA)- and oxalic acid (OA)-doped potassium dihydrogen phosphate (KDP) materials have been grown by slow evaporation solution technique. The structural parameters of the grown crystals have been determined using the single crystal X-ray diffraction technique. Fourier transform infrared analysis has been done to identify the functional groups of grown crystals. The modifications in optical transmittance, optical band gap and different optical constants of KDP crystal due to addition of MA and OA have been investigated by means of UV–Visible spectral analysis. The Vicker’s microhardness studies have been carried out to examine the mechanical behaviour of pure and doped KDP crystals. The influence of dopants on thermal stability of KDP crystal has been investigated using the thermogravimetric and differential thermal analysis. The dielectric constant, dielectric loss, ac resistivity and ac conductivity of pure and doped KDP crystals were evaluated under dielectric studies.