Syntheses of BiLa2O4 phosphors is carried out by single doping with Eu3+, Sm3+, Dy3+ and tri-doping with Eu3+/Sm3+/Dy3+ ions using high temperature solid reaction method. Characterization studies ...such as X-ray diffraction, diffuse reflectance spectra, photoluminescence excitation and emission spectra, decay profile measurements are made, in pursuit of a comprehensive analysis of the synthesized materials. As a result of XRD studies, the BiLa2O4 phosphors are found to have monoclinic structure. The luminescence properties of the of BiLa2O4 phosphors varies with different doping elements. The material is subjected to excitation at a wavelength of 464,462 and 422 nm. Strong emission peaks for Eu3+ ions at 626 nm with transition state (5D0 → 7F3), Sm3+ ions at a wavelength of 651 nm with a transition state (4G5/2 → 6H7/2) and Dy3+ ions at a wavelength of 575 nm with a transition state of (4G5/2 → 6H7/2) are observed. It is evident that the BiLa2O4 phosphors are potential candidates optoelectronic application because of the diverse luminescence properties showed on account of doping with different rare earth elements of Eu3+, Sm3+, Dy3+. The luminescence decay curve and chromaticity coordinates of BiLa2O4 phosphors single and tri-doped with Eu3+, Sm3+, Dy3+ have also been investigated.
•An organic triphenylmethane single crystal was grown by vertical Bridgman technique.•The band gap value of the grown crystal is estimated as 4.15 eV.•The SHG efficiency is 2 times of KDP.•The ...crystal posses low dielectric constant and dielectric loss values.
An organic triphenylmethane (TPM) single crystal of length 58 mm and diameter 12 mm was grown by vertical Bridgman technique. The cell parameters of the grown crystal were confirmed by single crystal X-ray diffraction studies. Powder X-ray diffraction analysis was used to determine the crystalline nature of the triphenylmethane crystal. The functional groups of the triphenylmethane crystal were identified by Fourier transform infrared analysis. The linear optical property of the grown triphenylmethane crystal was studied by UV–Vis–NIR spectroscopic analysis which shows that the crystal has low cutoff wavelength at 281 nm and exhibits optical band gap value at 4.15 eV. The fluorescence spectrum indicates that the grown crystal emits blue light. The second harmonic conversion efficiency of the crystal was determined using Kurtz and Perry powder technique. The thermal property of the grown crystal was analysed using thermo gravimetric analysis, differential thermal analysis and differential scanning calorimetry. The dielectric constant, dielectric loss and AC conductivity of the grown crystal was investigated for different frequency range upto 1 MHz at various temperatures. The strength of the crystal was estimated by Vicker’s hardness test and laser damage studies.
The Sr
1.95
Ba
0.05
CeO
4
:Eu
3+
phosphors are synthesized by the solid-state reaction method. The samples are characterized using X-ray diffraction (XRD), diffuse reflectance spectroscopy and ...photoluminescence (PL) spectra. The XRD results reveal that the synthesized phosphors are genuine crystalline and belong to the orthorhombic structure. The intense PL emission is optimized from the PL spectra at various doping concentrations of europium ions. The results indicates that the phosphor can be effectively excited under 264 nm wavelength producing on intense emission spectrum of the synthesis material at 484 nm (blue region). The color purity of the phosphor is confirmed by CIE coordinates (
x
= 0.217,
y
= 0.265). The experimental data indicate that the prepared phosphors can be used as blue-emitting material in the field of illuminations and display devices.
•Bi3+ & Dy3+ doped MLa2O4 (M=Sr, Ba & Ca) phosphors synthesized.•Effect of doping concentration and luminescence property discussed.•Tracing the energy transfer to rare earth element.
Syntheses of ...the MLa1.99-xO4:0.01Bi3+/xDy3+(M = Ba,Sr and Ca, and x = 0,0.02,0.05,0.08) phosphors are carried out by solid state reaction method. The samples are subjected to X-ray powder diffraction technique to determine the structure. According to the results, the Bi3+/Dy3+ ions have been substituted in the host materials in an effective manner. Furthermore, the diffuse reflectance spectroscopy throws light on the absorption spectrum with an observed peak around 300 nm owing to the host absorption band. An analysis of the luminescence properties of the synthesized materials using photoluminescence spectra points to an observed peak in the visible emission which stem from the energy states of 4F9/2→6H11/2,6H13/2,6H15/2 ground configuration of Dy3+ ions under UV excitation. As the concentration of Dy3+ ions increases from 0 to 0.05, an increase in emission peak intensity is observed. However, a further increase in concentration to x = 0.08 results in an abrupt drop in emission peak intensity because of the concentration quenching effect of emission spectra. The chromaticity coordinates are also calculated using CIE (1931), varying the concentration of Dy3+ ions. In a bid to obtain findings relating to decay time of the material, decay curves are drawn.
An organic nonlinear optical (NLO) material 4,4 super(3)-dimethoxybenzoin single crystal has been grown by vertical Bridgman technique using single wall ampoule. The grown crystal was confirmed by ...single crystal and powder X-ray diffraction (XRD) analyses. The functional groups of the grown crystal were identified by Fourier transform infra red analysis. The thermal behavior of the grown crystal were studied by thermo gravimetric (TG) and differential scanning calorimetric (DSC) analysis. The UV-vis-NIR spectrum has been recorded in the range 190-1100nm and it shows that the cutoff wavelength of grown crystal is around 343nm. The yellow emission of the grown crystal was identified by photoluminescence (PL) spectral measurements. The NLO property of the grown crystal was confirmed by Kurtz and Perry powder technique and the SHG efficiency of the grown crystal was found to be 2 times greater than KDP. The dielectric measurements were carried out and the results indicate that an increase in dielectric parameters with increase of temperature at all frequencies.
Lanthanum doped KTP crystal was grown using high temperature top seeded solution growth technique. The 0.08 wt.% of La super(3+) doping was confirmed by the EDAX analysis. Structural and variation of ...lattice parameters by doping were investigated by X-ray diffraction. The ferroelectric hysteresis loop was traced in polar axis of grown crystal. Static high frequency dielectric permittivity, suppressed electrical conductivity, low loss tangent, increase of resistivity and modulus properties were studied for lanthanum doped KTP crystal by broad band dielectric spectroscopy. Desirable low ionic conductivity was found as 4 x 10 super(-7) Omega super(-1) cm super(-1) in about 40 kHz frequencies.
The Sr0.95Ba0.05La2-xO4:xRE3+(RE = Eu,Er,Ce and Ho) phosphors are synthesized through high temperature solid-state reaction method at steps of 1000, 1100, 1200 °C. The impact of temperature on phase ...structures, functional group, luminescence properties and decay lifetime are investigated. The prepared Sr0.95Ba0.05La2-xO4 phosphors exhibit abundant luminescent properties with doping of different RE3+ ions under ultraviolet–visible and infrared excitation (980 nm) excitation. The Sr0.95Ba0.05La2-xO4:xEr3+ particles characterize red emission (4F9/2 → 4I15/2) through up-conversion emissions at 980 nm NIR irradiation. The chromaticity (CIE 1931) colour coordinates of the titled phosphors have also been evaluated. The merits of multicolor emissions in the visible region endow the synthesized material by UV irradiation reveals potential candidate in the field of light display systems, lasers and optoelectronic devices.
•Sr0.95Ba0.05La2-xO4 (SBLO):RE3+ (RE = Eu,Er,Ce and Ho) phosphors have been synthesized.•SBLO:RE3+ crystalline size depends on the rare earth elements and temperature.•Efficient up and down-conversion photoluminescence has been observed in Er3+:SBLO phosphors.•Annealing effect is studied on structural and luminescence properties of phosphors.
Organic material propyl 4-hydroxybenzoate (C
10
H
12
O
3
), single crystals, has been successfully grown by vertical Bridgman technique using the single and double wall ampoules. The grown crystal ...was confirmed by single crystal X-ray diffraction (XRD) and powder XRD analyses. Fourier Transform Infrared spectroscopy is used to identify the different functional groups. The thermal properties of the propyl 4-hydroxybenzoate were analysed. The single and double wall ampoules grown propyl 4-hydroxybenzoate crystals were also assessed by UV-vis-NIR, fluorescence and Vickers microhardness analyses. It is observed that the double wall ampoule gives better results than the single wall ampoule.
The SrLa
2−x
O
4
:xEu
3+
phosphors are synthesized through high-temperature solid-state reaction method at 1473 K with various doping concentration. Their phase structures, absorption spectra, and ...luminescence properties are investigated by X-ray diffraction (XRD), UV–Vis spectrophotometer and photoluminescence spectrometry. The intense absorption of SrLa
2−x
O
4
:xEu
3+
phosphors have occurred around 400 nm. The prominent luminescence spectra of the prepared phosphors exhibited bright red emission at 626 nm. The doping concentration 0.12 mol% of Eu
3+
is shown to be optimal for prominent red emission and chromaticity coordinates are x = 0.692, y = 0.3072. Considering the high colour purity and appropriate emission intensity of Eu
3+
doped SrLa
2
O
4
can be used as red phosphors for white light emitting diodes (WLEDs).
The butyl 4-hydroxybenzoate single crystal has been grown by vertical Bridgman technique using single wall ampoule. The cell parameters of the grown crystal are verified by single crystal X-ray ...diffraction analysis. The functional groups of the grown crystal were identified by Fourier transform infrared analysis. The melting, decomposition and crystallization point of the compound are determined by thermo gravimetric analysis and differential scanning calorimetric analysis. The mechanical properties of the grown crystal has been analyzed by Vickers microhardness method. The optical behavior of the grown crystal has been observed by UV–vis–NIR transmission spectroscopic analysis which shows that the lower cut-off wavelength lying at 293nm and found that the energy band gap value is 4.05eV. The blue light emission of the crystal was identified by photoluminescence studies. The positive third order nonlinear optical parameters like nonlinear refractive index (n2), nonlinear absorption co-efficient (β) and third order nonlinear susceptibility (χ3) of the grown crystal was calculated by Z-scan studies. The positive sign of nonlinear refractive index (n2) indicates that the crystal exhibits self focusing optical nonlinearity. The crystal exhibits good optical power limiting behavior.
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•Butyl 4-hydroxybenzoate single crystal was grown by vertical Bridgman technique.•The band gap value of the grown crystal is estimated as 4.05eV.•The PL emission at 430nm suggests that it is a blue light emitting material.•The n2 and χ3 values of crystal are 1.585×10−11m2/W and 7.264×10−6esu respectively.•Two photon absorption of the crystal is attributed for optical limiting applications.
