Pure Potassium Dihydrogen Phosphate Research Articles

Influence of potassium chloride doping on the properties of potassium dihydrogen phosphate crystal for nonlinear optical applications

Nonlinear optical single crystals of pure potassium dihydrogen phosphate and potassium chloride-doped potassium dihydrogen phosphate were grown by slow evaporation technique at room temperature. The powder X-ray diffraction analysis shows the reflection lines of the doped KDP crystal correlate well with the observed individual parent compound pure KDP with a slight shift in the intensity of the diffracted peaks. The crystal structure lattice parameters and space group was determined by single-crystal XRD studies. The existences of several functional groups were extricated by shifting of peaks in FTIR spectral inspections. The UV cut-off wavelength is found to be 381 nm for pure KDP 383 nm for potassium chloride-doped KDP crystals, respectively, using UV–Vis-NIR studies. The permittivity and dielectric loss tangent of the grown crystals are less at elevated frequencies with different temperatures. The correlative second harmonic (SHG) potency was evaluated by the Kurtz and Perry method for the doped crystal, and it was found to be 0.34 times higher than that of the pure KDP. The thermal stability measurement was carried out by TG/DTA study. Mechanical stability was found from load-dependent Vickers micro-hardness analysis.

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.

Synthesis,Crystal Growth Spectral and Optical Studies on Amino Acid Based New Novel NLO Single Crystal: L-Isoleucinium Phthalate (LIP)

Good quality colourless transparent nonlinear optical single crystals of L-Isoluecinium phthalate (LIP) was grown successfully by slow evaporation solution growth method from aqua solution at room temperature. Single crystals of LIP of dimensions 15mm x 8mm x 5mm were harvested after 50 days. The lattice parameter of grown crystal was studied by single crystal X- ray diffraction analysis and it was confirmed that the grown crystals belong to monoclinic crystal system with noncentrosymmetric space group of C2. Fourier transform infrared spectroscopic (FT-IR) studies was carried out using Jasco FT/IR 6300 Fourier transform infrared spectrometer by ATR method in the range of 400 – 4000 cm-1and it has been used to confirm the vibrational frequencies of various functional groups present in the crystal. Laser induced damage threshold study was carried using Q-Switced Nd: YAG laser and the laser power with the threshold value of 0.323 GW/cm2 also calculated. The UV-Vis-NIR spectroscopic study confirms that the crystal has good optical transparency and the cut off wavelength was found to be 300 nm. The band gap of the grown crystal was determined from the Tauc plot. The nonlinear optical property was confirmed by Kurtz Perry powder technique and it was compared with the standard pure potassium dihydrogen phosphate (KDP) crystals. In addition, a photoluminescence analysis was carried out for LIP crystal

Effect of l-threonine on growth and properties of ammonium dihydrogen phosphate crystal

Ammonium dihydrogen phosphate (ADP) is an important nonlinear optical (NLO) material used for electro-optical applications and finds various NLO applications using Nd:YAG and Nd:YLF Lasers. The Amino acids have properties like molecular chirality and zwitter ionic nature helps to improve NLO properties of ADP. The pure and l-threonine doped ADP crystals are grown using slow solvent evaporation technique at room temperature. The Powder XRD spectra suggest tetragonal crystal system and slight shifting of peak. The FT-IR spectra verify the presence of various functional groups of pure and doped ADP crystals. The FT-Raman shows strong absorption peak at 922 cm−1 due to asymmetric stretching of PO43− for all samples without shifting indicating the single phase nature of all samples. The photoluminescence study suggests the presence of defects in doped samples compared to the pure one due to increase of Stokes shift and vibrational energy relaxation phenomena. The presences of constituent elements are indentified using CHN analysis. The optical transmittance, energy band gap, skin depth, refractive index and extinction coefficient is study using UV–Visible spectroscopy and the dispersive behaviour of refractive index below absorption edge is study using Wemple-DiDomenico single oscillator model. The variation of capacitance and conductance is study using complex admittance spectroscopy. All the grown crystals have possessed negative photoconductivity. The second and third harmonic generation efficiency is increased nearly to double for l-threonine doped ADP crystals compared to pure Potassium dihydrogen phosphate (KDP). The laser damage threshold is measure for pure and doped ADP crystals.

Synthesis, growth and characterization of a new hydrogen bonded organic tosylate crystal: l-alaninium p-toluenesulfonate for second order nonlinear optical applications

An organic hydrogen bonded NLO material, l-alaninium p-toluenesulfonate (LAPT), was successfully synthesized and crystallized by slow evaporation solution growth technique with the dimension of 40 × 27 × 3 mm3. The crystal and molecular structures of LAPT were elucidated by single crystal X-ray diffraction technique. It reveals that the compound crystallized in a non-centrosymmetric orthorhombic space group P212121. The crystal packing features intricate three dimensional hydrogen bonding network which are observed at z = 1/4 and 3/4 and aromatic rings of the anions are stacked at x = 0 and 1/2. The molecular structure of the compound and its vibrational behaviour were analyzed by FTIR and FT-RAMAN spectral studies. UV–Vis–NIR spectral study revealed that the LAPT crystal has a wide transmission window in the entire visible region with the lower cutoff wavelength 282 nm. The luminescence study showed an ultraviolet emission of LAPT compound. TGA/DTA revealed the thermal stability of LAPT compound. The mechanical property of the title compound was analyzed by Vicker’s hardness test. The dielectric constant and dielectric loss of the crystal were measured as function of frequency at room temperature, and the results are discussed. The nonlinear optical property was confirmed by the Kurtz Perry powder technique and it was found to be two times higher than the pure potassium dihydrogen phosphate.

Synthesis, growth and characterisation of a semiorganic nonlinear optical material: l-threonine cadmium chloride single crystals

A semiorganic nonlinear optical single crystal was grown from aqueous solution by a slow evaporation method at room temperature. The characterisation of the crystal was made using single crystal and powder X-ray diffraction analysis and it was found to be the l-threonine cadmium chloride (LTCC) crystallised in an orthorhombic crystal system with noncentro symmetric space group. The UV–Vis spectroscopic study reveals that the crystal has good optical transparency and the lower cut off wavelength was found to be 332nm. The presence of functional groups was identified by FTIR spectra. The percentage of carbon, hydrogen and nitrogen was analysed by elemental analysis. The micro hardness was tested by using a Vicker’s micro hardness tester. The nonlinear optical property was confirmed by the Kurtz Perry powder technique and it was found to be 0.7 times higher than the pure potassium dihydrogen phosphate (KDP) crystal.

Broadband second-harmonic and sum-frequency generation in KH2PO4 crystals doped with anatase nanocrystals

Broadband second-harmonic (SH) and sum-frequency generation was studied in KH2PO4 crystals with incorporated anatase modification of titania nanocrystals. A tiny amount (10−5 wt.%) of titania nanoparticles in the anatase phase exhibits a pronounced (up to 15%) increase of the SH efficiency in comparison with the nominally pure potassium dihydrogen phosphate (KDP) crystal. Higher anatase fraction (10−4 wt.%) results in a reduction of the SH conversion efficiency. The rise of the SH signal is attributed to resonant excitation of the defect states at the nanocrystal interface, and its subsequent decrease at higher concentration is likely to be related to a light scattering in the crystal bulk.

Effect of Rare Earth Doped Elements and Characterization of LaF<sub>3</sub>:Ln<sup>3+</sup> (Ln<sup>3+</sup>= Ce<sup>3+</sup>, Pr<sup>3+</sup>, Nd<sup>3+</sup>) Nanocrystals

Abstract. LaF3 nanocrystals doped with lanthanides like Ce3+, Pr3+ and Nd3+ have been prepared using microwave technique. These synthesized crystals have been characterized by X-ray powder diffraction. Well dispersed, elongated, nanorods of hexagonal geometry (approximately 20nm in size) have been found in TEM analysis. The average particle size estimated from XRD analysis is about 20 nm and is in close agreement with the TEM results. Four characteristic peaks one at 3434 cm-1 (broad) and other at 2924, 2853, 1632 cm-1(sharp) have been observed in the FTIR spectra. Intense Blue colour (458 nm) emission has been recorded when crystals are excited with photons of wavelength 254 nm. Non Linear Optical (NLO) properties of the synthesized nanocrystals have been studied. It has been found that second harmonic generation (SHG) efficiency of the prepared samples containing rare earth elements is less than pure Potassium dihydrogen phosphate (KDP) crystals.

A Study on Structural, Optical, Electrical and Etching Characteristics of Pure and L-Alanine Doped Potassium Dihydrogen Phosphate Crystals

Pure potassium dihydrogen phosphate (KDP) crystals and KDP doped with L-alanine have been grown by slow evaporation technique at room temperature. Grown crystals have been characterized using powder X-ray diffraction, (XRD), Energy Dispersive X-ray spectroscopy (EDX) and Fourier Transform Infrared spectroscopy (FTIR). The presence of L-alanine into pure KDP crystal was confirmed by FTIR and EDX spectra. Crystal structure has been studied by XRD. Pure KDP and L-alanine doped KDP crystals both possessed tetragonal structure. The transparency is found to increase with the increase of doping concentrations of the grown crystals as observed by UV-Vis spectra. A.C. electrical conductivity of grown crystals along the growth axis was carried out at various temperatures ranging from 35?C - 400?C. Dielectric constant and dielectric losses are measured as a function of temperature and this study reveals the contribution of space charge polarization. Crystal defects and surface morphology are studied by dissolution solvent technique and reveals the step growth mechanism for both pure and doped crystals.

KDP:Mn piezoelectric coefficients obtained by X-ray diffraction

Crystals of pure potassium dihydrogen phosphate KH(2)PO(4) (KDP) and Mn-doped KDP (KDP:Mn) were grown from a water solution by the slow evaporation method and their piezoelectric properties were studied by X-ray diffraction methods. The results have shown an increase in the piezoelectric coefficients with the doping.

Growth and characterization of metal ions and dyes doped KDP single crystals for laser applications

The organic dyes (Amaranth, Rhodamine B and Methyl Orange) are doped in Potassium Dihydrogen Phosphate crystals. Influences of supersaturation and dye concentration in the solution, on the color and crystal habit of Potassium Dihydrogen Phosphate, were observed. Amaranth in the solution at low super saturation and high dye concentration colored the pyramidal section (1 0 1) of the crystals. The highly super saturated solutions produce entirely colored crystals. Dyes doped Potassium Dihydrogen Phosphate crystals were also grown by solution growth technique. The concentration of dopants in the mother solution was varied from 0.1 to 10 mol%. The studies on pure and doped Potassium Dihydrogen Phosphate crystals clearly indicate the effect of dopants on the crystal structure, in the absorption of IR frequencies and the non-linear optical property. The frequencies with their relative intensities are obtained in Fourier Transform-Infrared spectra of pure and doped Potassium Dihydrogen Phosphate. The very weak bands for dopants indicate its presence in low concentration. The absence of even such a weak band in the case of Potassium Dihydrogen Phosphate doped with Amaranth indicates the strong interaction with O–H groups. The calculated IR frequency 3333 cm −1 for O–H stretching was in close agreement with the experimentally obtained one for pure Potassium Dihydrogen Phosphate at 3340 cm −1.The doped crystals show good second harmonic generation efficiency. The dopants increase the hardness value of the material, which also depends on the concentration of the dopants. Dye doping improves the Nonlinear Optical properties of the grown crystals. Results of the growth kinetics of Potassium Dihydrogen Phosphate crystals in the presence of impurities are also discussed.

Giant crystals invade national lab

They're big, they're heavy, they're pure potassium dihydrogen phosphate. They're some of the world's largest fast-growth crystals, created at Lawrence Livermore National Laboratory (LLNL) in Livermore, Calif. In the image at right, researcher Randy Floyd poses with an imposing array of specimens. In fact, the crystal he's measuring is the largest of its ilk ever produced, grown in a mere 52 days and weighing a whopping 701 lb. Its measurements are 26 x 21 x 23 inches. The crystals have a purpose beyond looking pretty— they'll be sliced into plates and used to convert light from the giant laser at LLNL's National Ignition Facility from infrared to ultraviolet. The team of scientists who grew the crystals based their rapid-growth technique on one designed by Livermore researcher Natalia Zaitseva while she was a scientist in Russia in the late 1980s. The group, led by chemist Ruth Hawley-Fedder, immersed a thumbnailsized seed crystal inside a 6-foot-tall tank ...