Push-pull mixed-ligand d 8 -metal dithiolene complexes

Journal of Physics: Condensed Matter, 2007

When dealing with crystals showing self-frequency conversion properties, RbTiOPO 4 doped with Nb 5+ (RTP:Nb) is a better matrix than RTP for hosting luminescent ions in higher concentration. Therefore, we investigated the structural and the non-linear optical properties of RTP:Nb and RTP crystals for comparison. We used a new crystal growth process for RTP:Nb, which provides isometric inclusion-and crack-free crystals. Structural studies show that Nb 5+ ions are located in Ti positions only, which is confirmed by optical absorption and polarized Raman scattering studies. Moreover, the transparency domain of RTP:Nb is affected in the UV edge and in the IR region by the presence of Nb 5+ ions. Finally, we found that the fundamental wavelengths of type II angular non-critical phase-matching for second-harmonic generation along the x and y principal axes are smaller in RTP:Nb than in RTP, approaching those of KTP.

Le Journal de Physique Colloques

Spectroscopic properties of cr3+ doped KYP4012 and YP5014 crystals are presented for the first time. Both systems exhibit simultaneous broad-band 4~2 + and the weak narrow-band 2~ + A2 emissions. Ligand field parameter 10.Dq in KYP401Z: 5% cr3+ has been evaluated to be about 15500 cm". Time resolved spectra, lifetimes and 4 T2 effective emission cross sections have been studied in chromium doped Ytetraphosphates.

International Journal of ChemTech Research

In present investigation pure and KDP doped Cadmium Thiourea Acetate (CTA) crystals were grown by slow solution evaporation method at room temperature. The grown crystals were subjected to single crystal XRD to determine the volumetric parameters. The incorporation of KDP in CTA has been confirmed through the shifts in the vibrational frequencies of the grown crystals. The optical transparency of the grown crystals is examined in the range of 200-900 nm using UV-visible studies. The transmittance data was used to determine the optical band gap and essential optical constants viz. refractive index, extinction coefficient, reflectance, electrical susceptibility of grown crystal for possible nonlinear optical (NLO) applications.

Journal of Materials Science: Materials in Electronics, 2019

An optically good quality semiorganic single crystal of l-threoninium phosphate (LTP) was grown by solvent evaporation technique at room temperature. Single and powder XRD revealed the orthorhombic crystal structure of LTP with non-centrosymmetric space group Pna2 1. Linear optical behaviour of the title crystal was realized using UV-visible spectroscopy. The lower cutoff value was found to be 200 nm with broad optical transparency in entire visible region. Functional group and its bonding nature in the titular compound are explored by FTIR spectroscopic analysis. The LTP is thermally stable up to 241 °C and deferent level of decompositions with respect to temperature was analyzed using TG/DTA. Mechanical properties of LTP were studied using Vickers' microhardness tester. The fracture toughness (K c), Knoop hardness (H k), brittleness index (B i) and elastic stiffness constant (C 11) of LTP were calculated using micro-indentation data. Laser damage threshold value of LTP was found to be 4.92 GW/cm 2 which is convincingly high to use the crystal in lasing applications. The second harmonic generation efficiency of LTP is 2.1 times greater than the conventional KDP crystal. The nonlinear refractive index (n 2), the nonlinear absorption coefficient (β) and third-order nonlinear susceptibility (χ (3)) of the title crystal was found to be 1.19 × 10 −15 m 3 /W, 4.742 × 10 −9 m/W and 5.382 × 10 −14 m/W (esu) respectively. The single beam Z-Scan unit equipped with 532 nm continues wave laser was used to measure the third-order nonlinear optical parameters of grown crystal.

The structural, optical, mechanical, electrical and nonlinear properties of standard Ammonium Dihydrogen Phosphate (NH 4 H 2 PO 4 , ADP) single crystals incorporating organic Erioglaucine dye dopant are presented. The effect of Erioglaucine dye dopant at varied concentration on these properties has been investigated through measurement of powder X-Ray Diffraction (XRD), UV-Vis and photoluminescence spectroscopy, Vickers microhardness, light dependent I-V measurements and Second Harmonic Generation studies. These measurements reveal that doping with increasing dye concentration of Erioglaucine leads to change in properties of the ADP single crystals, making them suitable for optoelectronic applications. The Erioglaucine doped ADP single crystals were grown using solvent evaporation technique at room temperature. Optical properties like absor-bance and emission of these crystals are determined using UV-vis and photoluminescence spectroscopy, respectively. Optical bandgap and photoluminescence of the crystals are found to increase with dye doping, indicating their suitability in photonic applications. The mechanical properties of the crystals are determined using Vickers microhardness measurement technique. Light dependent I-V measurements exhibit negative photoconductivity behavior of the ADP crystals. However, the current through the crystals is observed to increase with increase in doping concentration of the Erioglaucine dye. Second Harmonic Generation studies show enhancement in nonlinearity for doped crystals. Our experiments indicate gradual variance in the crystallinity, emission, hardness, conductivity and nonlinearity of the sample with change in dye concentration.

Inorganic potassium dihydrogen phosphate (KDP) is widely known for its value as a nonlinear optical material. In this study, pure and L-arginine-doped KDP single crystals were grown by the slow solvent evaporation technique and further subjected to infrared absorption and Raman studies for the confirmation of chemical group functionalization and possible bonding between the organic and inorganic materials. The appearance in the infrared absorption spectra of additional vibrational lines, which mostly originate from disturbed N-H, C-H, and C-N bonds of the L-arginine-doped salt, confirm the interaction between KDP and the organic material. This affirmation is supported by more evidence from Raman measurements, where the disappearance of NH vibrations of the amino group is observed. We are thus led to the possibility of hydrogen bonding primarily between the nucleophilic O À of the phosphate unit of KDP and the amino group of the L-arginine.

Materials Research Bulletin, 2002

Chemical preparation, crystallographic characterization and vibrational studies are reported for two new condensed phosphates associated to nickel-rubidium NiRb 4 (P 3 O 9 ) 2 and strontium-thallium SrTl 4 (P 3 O 9 ) 2 . SrTl 4 (P 3 O 9 ) 2 was prepared by the method of ion-exchange resin and NiRb 4 (P 3 O 9 ) 2 was obtained by total thermal dehydration of NiRb 4 (P 3 O 9 ) 2 .6H2O. SrTl 4 (P 3 O 9 ) 2 is rhombhoedral , Z = 2, space group P-31c, with the following unit-cell parameters : a = 7,424(1) Å, c = 20,176(2) Å and V = 2807.46(2) (Å 3 ). NiRb 4 (P 3 O 9 ) 2 is triclinic, Z = 2, space group P-1, with the following unit-cell parameters : a = 8,046(9) Å , b = 9,733(0) Å, c = 4,327(5) Å, α = 98.053°, β = 88.616°, γ = 84.761° and V = 333,95(2) (Å 3 ). Vibrational study is also reported for the title compounds.

A nonlinear optical (NLO) material Potassium dihydrogen phosphates (KDP) and Ammonium dihydrogen phosphates (ADP) are grown by slow evaporation solution growth technique. The FTIR studies confirm the presence of the functional group in the grown crystal. The optical transmittance studies show that the crystal has transparence in the entire visible and IR region. The thermal stability of the materials was assessed by TG/DTA analysis. The mechanical stability of the grown crystals was analyzed by Vicker's microhardness test. The dielectric behavior of the crystals was tested by dielectric analysis. The second harmonic generation (SHG) of KDP is confirmed by Kurtz and Perry powder technique using Nd: YAG laser.

Journal of Crystal …, 2005

Amino acid family crystals have over the years been subjected to extensive investigation by several researchers for their non-linear optical (NLO) properties. l-arginine phosphate monohydrate (LAP), an NLO crystal, was first reported by Xu et al. [1]. LAP crystal has drawn the ...

Present research work exhibit perfect reinforcing in different optical parameters of thiourea metal complex (TMC) on potassium dihydrogen phosphate (KDP) crystal. The pure and TMC doped KDP crystals were grown by slow evaporation solution technique. The optical traits of the doped crystal have been systematically examined by UV-visible spectral analysis within the wavelength range of 200-800 nm. This investigation presents the detail study of optical properties transmittance, band gap, refractive index, reflectance, extinction coefficient, optical conductivity, real dielectric constant and imaginary dielectric constant of TMC doped KDP crystal. The Kurtz-Perry powder test has been employed to determine the enhancing effect of thiourea metal complex on the second harmonic generation (SHG) efficiency of KDP crystal and it found to be 1.78 times reference material.