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Tanusree Kar - One of the best experts on this subject based on the ideXlab platform.

  • growth and characterization of nonlinear optical crystal zinc tris thiourea sulphate in presence of l arginine
    Optical Materials, 2007
    Co-Authors: Sweta Moitra, Tanusree Kar
    Abstract:

    Abstract The present communication deals with the single crystal growth and characterization of zinc tris (thiourea) sulphate (ZTS) Doped with different molar concentrations of basic amino acid l -arginine. Doped single Crystals of ZTS were grown by solvent evaporation method at constant temperature (35 °C). Doped Crystals exhibit prominent morphological changes in different crystallographic planes. Incorporation of l -arginine in ZTS Crystals has been estimated qualitatively by Fourier transformed infrared spectra. Lattice parameters were determined by powder X-ray diffraction analysis. The influence of the organic impurity on optical and mechanical properties has also been studied.

Thomas R Shrout - One of the best experts on this subject based on the ideXlab platform.

  • characterization of mn modified pb mg1 3nb2 3 o3 pbzro3 pbtio3 single Crystals for high power broad bandwidth transducers
    Applied Physics Letters, 2008
    Co-Authors: Shujun Zhang, Sungmin Lee, Dongho Kim, Hoyong Lee, Thomas R Shrout
    Abstract:

    The effect of MnO2 addition on the dielectric and piezoelectric properties of 0.4Pb(Mg1∕3Nb2∕3)O3–0.25PbZrO3–0.35PbTiO3 single Crystals was investigated. Analogous to acceptor doping in “hard” Pb(Zr,Ti)O3 based polycrystalline materials, the Mn Doped Crystals exhibited enhanced mechanical Q (∼1050) with low dielectric loss (∼0.2%), while maintaining ultrahigh electromechanical coupling k33>90%, inherent in domain engineered single Crystals. The effect of acceptor doping was also evident in the build-up of an internal bias (Ei∼1.6kV∕cm), shown by a horizontal offset in the polarization-field behavior. Together with the relatively high usage temperature (TR-T∼140°C), the Mn Doped Crystals are promising candidates for high power and broad bandwidth transducers.

  • growth and characterization of fe Doped pb zn1 3nb2 3 o3 pbtio3 single Crystals
    Journal of Applied Physics, 2003
    Co-Authors: Shujun Zhang, Laurent Lebrun, Daeyong Jeong, Clive A Randall, Q M Zhang, Thomas R Shrout
    Abstract:

    Fe-Doped 0.955Pb(Zn1/3Nb2/3)O3−0.045PbTiO3 (PZNT4.5) single Crystals were grown using a high temperature flux technique and the dielectric, piezoelectric, electromechanical, electrostrictive, and electro-optic properties were characterized. The room temperature dielectric permittivity along the direction after poling was about ∼6000 (5000−7000), increased compared to that of pure PZNT4.5 Crystals ∼3000−5000. The Curie temperature (TC) and the rhombohedral to tetragonal phase transition temperature (Tr−t) of Doped Crystals were about 143 and 92 °C, respectively, more than 20 °C lower than that of the pure Crystals. The remnant polarization (Pr) and coercive field (Ec) of oriented Doped Crystals measured at 1 Hz and 20 kV/cm field were ∼27.3 μC/cm2 and 4.7 kV/cm, respectively, the latter significantly greater than the Ec of the pure Crystals ∼3 kV/cm. Piezoelectric coefficients (d33) of oriented Doped PZNT4.5 Crystals were ∼2500−3000 pC/N, being much higher than that of the pure (1400–2000...

Mohd Shkir - One of the best experts on this subject based on the ideXlab platform.

  • effect of ni2 doping on structural optical mechanical and dielectric properties of ammonium dihydrogen phosphate adp single Crystals a novel nlo material
    Optik, 2016
    Co-Authors: V Ganesh, Mohd Shkir, S Alfaify, Mahmoud A Sayed
    Abstract:

    Abstract Owing to its exceptional applications in nonlinear optical devices, ammonium dihydrogen phosphate (ADP) is considered as potential candidate in modern era of hi-tech applications. Therefore, in the present work we have grown good quality single Crystals of pure and Ni 2+ Doped (1, 2.5% and 5%), ADP using slow evaporation technique. X-ray study has been carried out in order to see the effect of dopant on the structural parameter of ADP. The UV–vis–NIR studies confirmed that 1.0 mol%, 2.5 mol% Doped Crystals have high transmittance compare to 5.0 mol% Ni 2+ Doped ADP Crystals. Surface studies have been carried out on pure and Doped Crystals. Typical striations are observed on the (100) faces of pure and Doped Crystals, suggest that the growth occurs by 2D nucleation. The microhardness studies of pure and Doped Crystals carried out at different loads. The hardness of 5.0 mol% Ni 2+ Doped Crystals shows higher hardness value compare to 1.0 mol%, 2.5 mol% Doped Crystals. The mechanical properties such as fracture toughness ( K c ), brittleness index ( B i ) and yield strength ( σ y ) are presented. The dielectric studies were carried out in the high frequency range (1–6 MHz) and all the results indicate that the grown Crystals are of good quality.

  • effect of titan yellow dye on morphological structural optical and dielectric properties of zinc tris thiourea sulphate single Crystals
    Journal of Materials Research, 2016
    Co-Authors: Mohd Shkir
    Abstract:

    Zinc(tris) thiourea sulphate (ZTS) is as one of the potential candidates for nonlinear optical applications due to its high nonlinearity and excellent optical properties. The synthesis of pure and titan yellow dye Doped ZTS has been done and good quality rod-like single Crystals of size ∼60 mm long and 2 mm diameter were grown through simplest and low cost route. The structural and vibrational analysis rules out any extra phase or change in structure of ZTS due to dye doping. Scanning electron microscope study reveals that the grown Crystals are of good quality with rod-like morphology. Diffuse reflectance spectrum show a new absorption band at ∼460 nm, which may be predicted as a signature of dye. The optical band gap was calculated to be 4.6 eV for pure and 4.5 eV for Doped ZTS Crystals. The violet-blue emission centered at 412 nm in pure and at 414 nm in Doped Crystals with an additional green emission bands at 528 nm with high intensity in the photoluminescence spectra were observed. The value of e 1 is found to be enhanced from 10 (in pure) to 14 (in Doped) Crystals. The properties are enhanced due to dye doping and may be more useful than pure Crystals in optoelectronic devices.

R Jayavel - One of the best experts on this subject based on the ideXlab platform.

  • effect of amino acid doping on the growth and ferroelectric properties of triglycine sulphate single Crystals
    Materials Research Bulletin, 2008
    Co-Authors: C M Raghavan, Raman Sankar, Mohan R Kumar, R Jayavel
    Abstract:

    Effect of amino acids (L-leucine and isoleucine) doping on the growth aspects and ferroelectric properties of triglycine sulphate Crystals has been studied. Pure and Doped Crystals were grown from aqueous solution by low temperature solution growth technique. The cell parameter values were found to significantly vary for Doped Crystals. Fourier transform infrared analysis confirmed the presence of functional groups in the grown crystal. Morphology study reveals that amino acid doping induces faster growth rate along b-direction leading to a wide b-plane and hence suitable for pyroelectric detector applications. Ferroelectric domain structure has been studied by atomic force microscopy and hysteresis measurements reveal an increase of coercive field due to the formation of single domain pattern.

  • effect of rare earth dopants on the growth and properties of triglycine sulphate single Crystals
    Journal of Crystal Growth, 2002
    Co-Authors: R Muralidharan, R Mohankumar, P M Ushasree, R Jayavel, P. Ramasamy
    Abstract:

    Abstract The effect of rare-earth ion dopants La, Ce and Nd on the growth aspects and ferroelectric properties of triglycine sulphate single Crystals is reported. The incorporation of dopants into the grown Crystals is far below the concentration in the mother solution. The dopants significantly modify the morphology of the Crystals. Dielectric measurements revealed that the dielectric constant of Ce Doped triglycine sulphate (TGS) increases rapidly at the transition temperature. Well-saturated rectangular hysteresis loops have been observed for all the Doped Crystals. Lenticular ferroelectric domain patterns were observed on the [0 1 0] plane of the grown Crystals. Among the three dopants, La Doped TGS possess a high Curie temperature and coercive field values.

Mansoor Sheikbahae - One of the best experts on this subject based on the ideXlab platform.

  • tm Doped Crystals for mid ir optical cryocoolers and radiation balanced lasers
    Optics Letters, 2019
    Co-Authors: Saeid Rostami, Alexander R Albrecht, Azzurra Volpi, Markus P Hehlen, M Tonelli, Mansoor Sheikbahae
    Abstract:

    We report the complete characterization of various cooling-grade Tm-Doped Crystals including, to the best of our knowledge, the first demonstration of optical refrigeration in Tm:YLF Crystals. Room temperature laser cooling efficiencies of 1% and 2% (mol) Tm:YLF and 1% Tm:BYF Crystals at different excitation polarizations are measured, and their external quantum efficiency and background absorption are extracted. By performing detailed low-temperature spectroscopic analysis of the samples, global minimum achievable temperatures of 160 to 110 K are estimated. The potential of Tm-Doped Crystals to realize mid-IR optical cryocoolers and radiation balanced lasers (RBLs) in the eye-safe region of the spectrum is discussed, and a promising two-tone RBL in a tandem structure of Tm:YLF and Ho:YLF Crystals is proposed.