Potassium Hydrogen Phthalate Crystals Research Articles

Effect of urea on optical properties of potassium hydrogen phthalate (KHP) single crystals for NLO applications

Semi-organic carbamide (urea) doped potassium hydrogen phthalate (KHP) crystals grown from slow evaporation solution growth technique. The grown crystals were subjected to powder XRD analysis and doped KHP crystallizes in orthorhombic structure with space group Pca21. FTIR spectrum confirms the presence of major functional groups and shows minor distortion of functional groups due to effect of dopant. SEM studies revealed, the effectiveness urea dopant on surface morphology of grown crystals. From thermal studies, it is found that, both undoped and urea doped KHP were stable up to 300 °C. UV–Visible studies showed, the grown crystals were transparent in the entire visible region and calculated optical band gap from Tauc’s plots. The SHG studies of the grown crystals have been confirmed by Kurtz-Perry powder technique.

Growth, XRD, optical, thermal, mechanical, electrical and NLO studies on mixture of potassium hydrogen phthalate and L-tartaric acid crystal for NLO applications

Growth, XRD, optical, thermal, mechanical, electrical and NLO studies on mixture of potassium hydrogen phthalate and L-tartaric acid crystal for NLO applications

Effect of thiourea on the growth, optical, thermal, mechanical and dielectric properties of potassium hydrogen phthalate crystal

Pure and 1 mol% thiourea doped potassium hydrogen phthalate single crystals were grown by slow evaporation method. Single crystal XRD confirms the crystalline perfection of the crystal. FTIR studies confirm the presence of functional group. UV–Vis studies reveal the good optical transparency of the crystal. The thermal stability of the crystal was confirmed by thermal studies. The strength of the crystal was determined by Vickers micro hardness studies. The dielectric constant and dielectric loss at various temperatures was determined. The nonlinear optical efficiency of 1 mol% thiourea doped KHP and pure KHP crystal was identified by SHG studies.

Growth, optical, thermal, mechanical, dielectric, electrical and nonlinear optical properties of pure and sodium thiosulphate doped potassium hydrogen phthalate crystal

Single crystals of sodium thiosulphate (ST) incorporated potassium hydrogen phthalate (KHP) crystals were grown by slow evaporation method at room temperature. The concentration of ST in the KHP solution was 1 mol%. The single crystal and powder X-ray diffraction confirm the orthorhombic crystal system and crystalline perfection of ST doped KHP crystal. FT-IR analysis confirm that the crystal undergoes appreciable alteration as a result of the incorporation of dopant. The optical transparency was revealed by UV–visible spectroscopic study and thermal analyses shows the thermal behavior of the crystal. Mechanical stability was evaluated by Vicker microhardness testing. SEM pictures give the surface morphology and energy dispersive X-ray analysis confirms the incorporation of ST in KHP. The crystals were undergone a frequency-dependent dielectric study. The dc electrical studies are also carried out for a pure and ST doped KHP crystal. The optical nonlinearity is confirmed by using the Kurtz-Perry powder technique.

Structural, optical, and mechanical properties of gamma beam-irradiated pure and CeCl3-doped potassium hydrogen phthalate (KHP) crystals for scintillating applications

Potassium hydrogen phthalate (KHP) is a high-energy scintillating material having superior properties. The solution crystal growth technique at room temperature is employed for growing undoped and CeCl3-doped KHP crystals. The 60Co γ-ray-irradiated crystals were analyzed through powder X-ray diffraction analysis to evaluate the cell parameters of the pure and doped KHP crystals. The functional groups and vibration modes were identified by Fourier transform infrared spectral analysis. The optical transparency of the grown crystals was analyzed by UV–vis spectroscopy which shows less absorption in the CeCl3-doped KHP crystals when compared to pure KHP. The vibration properties were discussed with the use of Raman spectra of pure and doped crystals. The photoluminescence analysis reveals broad peaks from green to violet ranges for undoped and CeCl3-doped KHP crystals. The microhardness test was carried out at different applied loads varying in the range 25–100 g. It is revealed that the Vicker’s hardness values (Hv) increase with increasing applied load. The Meyer’s index number (n) is determined and it confirms that the gamma-irradiated pure, CeCl3-doped KHP crystals belong to the soft material category. The mechanical properties such as the elastic stiffness constant (C11), yield strength (σv), brittleness index (Bi), and the fracture toughness (Kc) are measured for both pure and 1–4 mol% CeCl3-doped KHP crystals.

Gamma ray irradiation and characterization on urea and thiourea doped potassium hydrogen phthalate (KHP) crystals

Potassium hydrogen phthalate (KHP) is a semi-organic transparent crystal that offers very good energy scintillation characteristics and its wide applications as Non-linear optical materials. In the present work pure and urea, thiourea doped KHP crystals were grown from solution growth technique at room temperature. Gamma-beam irradiated crystals were exposed to powder x-beam diffraction and cross section lattice parameters were assessed. The Fourier transform infrared spectrum analysis confirms the presence of functional groups due to the doping of urea and thiourea materials and its irradiation effects. UV–vis and photoluminescence investigation uncovered to comprehend the optical properties. Urea, thiourea doped Potassium hydrogen phthalate crystals were high scintillators. The Vickers micro-hardness estimations for various loads were done for developed crystals and the mechanical stability of the unadulterated and urea, thiourea doped KHP crystal tests were resolved. As the load builds, the estimation of Vickers miniaturized scale hardness diminishes. The urea, thiourea doped crystals are seen as milder than unadulterated KHP.

Effect of organic additive on the growth and characterization of potassium hydrogen phthalate crystals: third-order nonlinear optical properties

Potassium hydrogen phthalate (KHP) single crystals were grown in the presence of an organic additive, 1,5-diaminonaphthalene. The effect of the additive on surface morphology and optical properties has been studied. The sharp prominent peaks in the indexed powder X-ray diffraction (PXRD) pattern confirm the crystallinity of the sample and comparison with XRD pattern of pure reveals the stress on KHP structure and it is further supported by minor shifts in IR frequencies. Scanning electron microscope investigation reveals surface morphological changes. Third-order nonlinear optical (NLO) properties of the KHP crystals grown from alcoholic solution containing 1,5-diaminonaphthalene were derived by employing a single beam Z-scan technique at a wavelength of 532 nm with He-Ne Laser system.

Effect of xylenol orange dye on morphological, optical, piezo-/di-electric and mechanical properties of potassium hydrogen phthalate single crystals

Pure and xylenol orange (XO; C13H32N2O13S;0.1 mol%) dye doped potassium hydrogen phthalate (KAP; C8H5KO4) crystal were grown by solution technique. Only {111‾} & {110} growth sectors of KAP crystal got selectively stained by the XO dye molecules with {010} being the largest visible (morphologically important) plane. Powder XRD pattern reveals that XO dyeing did not resulted in any extra Bragg peaks and hence, didn't changed the basic structure of KAP crystal (PCa21). HRXRD and etch pit density studies were performed to investigate the effect of XO dye staining on the crystallinity of KAP crystal.The Piezoelectric charge coefficient increased (1.42–1.62 pC/N), optical transparency increased (30%–50%), mechanical strength improved (10.2–11 kg/mm2 @ 20 g), dielectric constant enhanced (ε' ~40 to 44 @ 1 kHz) and dielectric loss decreased (~0.09 to ~0.02) due to XO dye doping. Comparative optical, mechanical, piezoelectric and dielectric investigations add to the scientific insights of KAP crystals and suggest XO-dyed KAP crystal as a better alternative than pure KAP crystal for opto-electronic devices applications.

Material synthesis and characterization of NLO-active potassium hydrogen phthalate fumaric acid semiorganic crystal for frequency conversion

The fumaric acid potassium hydrogen phthalate (KHPF) crystal was grown by slow evaporation technique at ambient room temperature. The structural properties of grown KHPF crystals have been studied by the single-crystal X-ray diffraction analysis. The sharp Bragg peaks were observed from powder X-ray diffraction study. The functional groups present in the sample were analyzed from Fourier transform infrared spectrometer. The lower UV cutoff wavelength at 295 nm was obtained from UV–visible–NIR study. The second harmonic generation efficiency of the grown KHPF crystal was found to be 1.07 times as that of standard KDP. The fluorescence properties of KHPF crystal have been studied by photoluminescence study. The thermal property of the grown KHPF crystal was carried out from TG/DTA curve and the melting point is 237.99 °C.The mechanical behaviour of the grown KHPF crystal was investigated by Vicker’s micro-hardness test. From the calculation of work-hardening coefficient, the grown KHPF crystal belongs to soft category. The microstructure analysis of the grown crystal was carried out by SEM analysis.

Linear and Nonlinear Optical Constants of Potassium Acid Phthalate crystal

Single crystals of potassium hydrogen phthalate (KAP) are grown by solution growth technique. Linear optical constants are evaluated from UV/VIS/NIR spectrum. The Z scan technique is used to elucidate the third order nonlinearity in the material. The results indicate that the compound exhibits reverse saturable absorption (RSA) and self-defocusing performance. The second harmonic generation (SHG) efficiency of the crystal evaluated by Kurtz and Perry technique is compared with that of the standard KDP crystal. Attempt is made to correlate the SHG efficiency with the crystalline perfection in the material. Full Text: PDF ReferencesMiniewicz.A, Barkiewics.S, "On the electro‐optic properties of single crystals of sodium, potassium and rubidium acid phthalates", Adv.Mat.Opt.Elect,2,157(1993). CrossRef Comeretto.D, Rosy.L, "Optical properties of potassium acid phthalate", J.Mat.Res, 12, 1262(1997). CrossRef Krajewski.T, Breczewski.T, "Dielectric and pyroelectric properties of TGS crystals doped with nitroaniline molecules", Ferroelectrics, 25, 547 (1980). CrossRef N. Kejalakshmy, K. Srinivasan, "Growth, optical and electro-optical characterisations of potassium hydrogen phthalate crystals doped with Fe3+ and Cr3+ ions", Opt. Mater. 27,389–394A, (2004). [5] CrossRef Ester. G.R, Price.R, Halfpenny. P.J, "An atomic force microscopic investigation of surface degradation of potassium hydrogen phthalate (KAP) crystals caused by removal from solution", J.Cryst.Growth, 182, 95(1998). CrossRef Hiroyuki Toda, Carl M. Verber "Simple technique to reveal a slow nonlinear mechanism in a z-scanlike n2 measurement", Opt. Lett. 17(19) 1379(1992). CrossRef K.J. Arun, S.Jayalekshmi, "Investigations on the nonlinear optical properties of glycinium oxalate single crystals", Optoelectron. Lett. 7(2), 136, (2011). CrossRef K.J.Arun, S.Jayalekshmi, "Third order nonlinear optical constants of L-alaninium oxalate", Phot. Lett. Poland 7(3), 81-83 (2015) CrossRef

Anisotropy of the Resonance Transformation of the Microhardness of Crystals after Their Exposure in the EPR Scheme in the Earth’s Magnetic Field

It is shown that the preliminary exposure of ZnO, triglycine sulfate, and potassium hydrogen phthalate crystals in ultralow crossed magnetic fields—Earth’s magnetic field and ac pump field—leads to a resonance change in their microhardness. The resonance frequency of microhardness peaks is determined by the classical condition of electron paramagnetic resonance only at certain orientations of the crystals with respect to the Earth’s magnetic field BEarth. Rotations of all samples with respect to the direction BEarth by angle θ reduce the resonance frequency in proportion to cosθ. The observed anisotropy has been attributed to the presence of their own local magnetic fields Bloc ≫ BEarth in the crystals.

Growth and characterization of succinic acid-mixed KHP crystal for NLO applications

Semiorganic single crystals of succinic acid-mixed potassium hydrogen phthalate (KHPSA) were grown from an aqueous solution by the slow evaporation method at room temperature. The structural properties of the grown crystals have been studied by single-crystal X-ray diffraction, powder X-ray diffraction and Fourier transform infrared spectral analysis. Ultraviolet (UV)–visible spectral analysis showed that the mixed crystal has a lower UV cutoff wavelength of 226 nm combined with good transparency of about 55% in a very wide range. The second harmonic generation efficiency test has been carried out and the results are discussed. Thermogravimetric–differential thermal analyses were carried out to characterize the melting behavior and thermal stability of the mixed crystal. The hardness profile of the sample is investigated by using the Vickers microhardness test. The electrical properties have been studied by carrying out dielectric constant studies. Determination of the microstructure and composition of the KHPSA crystal has been carried out by scanning electron microscopy with energy-dispersive spectroscopy.

Effect of Manganese (Mn) – doping on crystalline and optical properties of Potassium Hydrogen Phthalate (KHP) crystals

Single crystals of Manganese (Mn)-doped Potassium Hydrogen Phthalate (KHP) were grown by slow evaporation solution growth technique using water as solvent at room temperature. The grown single crystals were analysed with powder X-ray diffraction (XRD) and estimated lattice parameters. FT-IR studies confirmed the presence of functional groups and slight distortion of groups due to doping. UV–Visible spectral studies on samples showed the improved transparency of doped crystals in the entire visible-near infrared region and calculated band gap from Tauc’s plots. The SHG efficiency studies were carried out for grown doped crystals by Kurtz-Perry powder technique.

Growth and Characterization of Pure and L-Phenylalanine doped Potassium Hydrogen Phthalate Crystals

Growth and Characterization of Pure and L-Phenylalanine doped Potassium Hydrogen Phthalate Crystals

Mechanical Studies on Pure and Fe<sup>3+</sup> Doped Potassium Hydrogen Phthalate Single Crystals for Device Fabrications

Background/Objectives: Mechanical properties of the selected materials play an important role in device fabrications. Thus the perfect cleavage (010) plane of doped and un-doped Potassium Hydrogen Phthalate (KHP) crystal is subjected to Vicker’s micro hardness study. Methods/Statistical Analysis: Slow evaporation solution growth method is employed for the growth of Fe 3+ doped and un-doped Potassium Hydrogen Phthalate (KHP) crystals. Here, 0.1 mol% of FeCl 3 used as dopant. Saturated solution of both doped and un-doped KHP solutions are prepared according to the solubility data (12.5g/100ml at 30°C). Findings: A well developed (010) plane of pure and un-doped crystals have been subjected to hardness studies with various loads. It is found that Vickers Hardness numbers ( H V ) for undoped and doped KHP crystals varied for different loads. Meyer’s index or work hardening co-efficient ( n ) values are found to be greater than 1.6 which reveals that the grown crystals are belongs to soft material’s category. i.e., for pure KHP the value of ‘n’ is 3.68 and for Fe doped KHP, it is 3.46. The minimum load indentation ( W ) to initiate the plastic deformation on the surface of the crystals are calculated based on Hays and Kendall’s theory. The value of W for KHP and doped KHP are found to be 1.965 and 4.368 respectively. The hardness related constants like materials constant ( k 1 ) and load dependent constant ( A 1 ) for the pure and un-doped KHP crystals have been estimated. The Elastic stiffness constant ( C 11 ) are also calculated from Vickers micro hardness values. Applications/Improvements: Potassium Hydrogen Phthalate (KHP) is an efficient crystal analyzer material and is used in X-ray spectrometer. The improvement in hardness by dopant provides the use of materials for efficient optical device applications.

Gamma irradiation effects on crystalline and optical properties of pure and doped Potassium Hydrogen Phthalate (KHP) single crystals

The undoped and urea doped semi-organic nonlinear optical Potassium Hydrogen Phthalate (KHP) crystals were grown by solution growth slow evaporation technique at room temperature. Grown crystals were irradiated with gamma rays using 60Co radioactive source. Grown crystals were irradiated with different dose from 100krad to 5Mrad. Irradiated and unirradiated crystals were subjected to powder x-ray diffraction and lattice parameters were calculated. It was also observed, slight colour change of crystals with increase in the dose of irradiation. The functional groups of irradiated undoped and urea doped KHP crystals were identified from FTIR spectral studies. The UV–vis spectrum reveals an increase in the optical absorption with increase in gamma dose in undoped and doped KHP. From Tauc the plot optical band gap is estimated and found to decrease with increase in gamma dose. Second harmonic generation (SHG) efficiency was confirmed by Kurtz-Perry powder method and SHG values decreases with increase in radiation dose.

Resonance magnetoplasticity in ultralow magnetic fields

Resonance relaxation displacements of dislocations in NaCl crystals placed in crossed static and alternating ultralow magnetic fields in the electron paramagnetic resonance scheme are discussed. The Earth’s magnetic field B Earth ≈ 50μT and other fields in the range of 26–261 μT are used as the static field. New strongly anisotropic properties of the effect have been revealed. Frequency spectra including numerous peaks of paths at low pump frequencies beginning with 10 kHz, as well as the quartet of equidistant peaks at high frequencies (~1.4 MHz at B=B Earth), have been measured. The effect is also observed in the pulsed pump field with a resonance duration of ~0.5 μs. Resonance changes have been detected in the microhardness of ZnO, triglycine sulfate, and potassium hydrogen phthalate crystals after their exposure in the Earth’s magnetic field in the same electron paramagnetic resonance scheme.

Optical, spectral and dielectric studies of l-histidine added potassium hydrogen phthalate crystals

Optically transparent pure and amino acid added potassium hydrogen phthalate (KHP) single crystals were grown by slow evaporation technique at 32°C. The entry of amino acid in the parent compound was confirmed by powder X-ray diffraction by the change in lattice parameters and also from the presence of amino group in the FT-IR and FT-Raman spectra in the case of amino acid added KHP crystals. The thermal and mechanical stability of the crystal was increased by the addition of amino acid. The optical studies revealed that the crystals have high transmittance in the entire visible region. The PL yield was also high for the crystals at 523nm when excited with 480nm. The SHG measurement confirms the emission of green light and the addition of amino acid has increased the SHG efficiency of the crystal. The crystals were also subjected to the dielectric study by varying the temperature and frequency.

Synthesis, growth, structure and characterization of potassium lithium hydrogen phthalate mixed crystals

Mixed crystals of lithium-incorporated potassium hydrogen phthalate were grown by the slow evaporation solution growth technique from an aqueous solution containing equimolar quantities of potassium hydrogen phthalate (KHP) and lithium carbonate.

Effect of NaCl Doping on Growth, Characterization, Optical and Dielectric Properties of Potassium Hydrogen Phthalate (KHP) Crystals

Single crystals of sodium chloride doped Potassium Hydrogen Phthalate (KHP) were grown from aqueous solution by slow evaporation method at room temperature. The powder X-ray diffraction analysis was carried out and lattice cell parameters estimated. FTIR studies confirm the presence of functional groups and slight distortion of groups due to doping of sodium metal. UV-visible and photoluminescence spectral studies revealed to understand the optical properties. The NLO property of grown crystals has been confirmed by Kurtz powder technique. Dielectric studies of samples showed that dielectric constant decreased slowly with increasing frequency and attains saturation at higher frequencies.