Vinay Kumar

Central University of Jammu · Department of Physics

Luminescence characteristics and surface chemical changes of nanocrystalline Mn2+ doped ZnAl2O4 powder phosphors are presented. Stable green cathodoluminescence (CL) or photoluminescence (PL) with a maximum at ∼512 nm was observed when the powders were irradiated with a beam of high energy electrons or a monochromatic xenon lamp at room temperature...

Tb3+-doped porous LiAl5O8 nanophosphors were successfully synthesized using a single step combustion method. Structural characterization of the luminescent material was carried out with X-ray diffraction (XRD) analysis and high resolution transmission electron microscopy (HRTEM). Surface composition was estimated from X-ray photoelectron and Auger...

The effects of accelerating voltage (0.5–5 keV) on the green cathodoluminescence (CL) of CaS : Ce ³⁺ nanocrystalline powder phosphors is reported. An increase in the CL intensity was observed from the powders when the accelerating voltage was varied from 0.5 to 5 keV, which is a relevant property for a phosphor to be used in field emissi...

Undoped and a series of Dy³⁺ activated Sr2B2O5 phosphors were synthesized using the solution combustion technique and further annealed at 900 °C for better crystallinity. The powder X-ray diffraction results confirmed the single-phase monoclinic structure with the P21/c space group and the crystallite size was estimated using the Debye Scherrer for...

The present work reports the preparation of KSr(1 − 3x/2)VO4:xTb3+ powders (x = 0 to 5.0 mol%) via low-cost combustion route. The XRD study affirms the phase purity of the phosphors and established the nano-size of the powdered grains which is also supported by Transmission Electron Microscopy (TEM) studies. The UV–Vis spectroscopy reveals that the...

Using a low-cost solution combustion method, CaSr2(PO4)2 orthophosphate phosphors doped with Eu³⁺ were prepared and examined as non-contact optical thermometers and solid state lighting sources. The synthesized phosphors were characterized via X-ray diffraction (XRD), photoluminescence spectroscopy (PL), Fourier transform infrared spectroscopy (FTI...

Orange-red light emitting LiSr(1-x)P3O9:xSm³⁺ phosphors were successfully prepared by the Solution combustion method. The Powder X-ray Diffraction analysis confirmed a single phase for the samples with a crystallite size ranging from 66±0.9 nm to 72±0.5 nm. The photoluminescence (PL) spectra revealed that at 398 nm excitation, the LiSrP3O9:Sm³⁺ pho...

Thermoluminescence response and trapping parameters of the Zn3(VO4)2 phosphors synthesized by the combustion had been studied. The phase and crystal structure of the phosphor was confirmed by powder X-ray diffraction.Thermoluminescence (TL)response of the material was investigated against gamma-rays in the range of 1-20kGy. The TL glow curves of th...

A near-UV-converted Dy³⁺ doped LiSrP3O9 phosphors were synthesized using a combustion synthesis route and were explored for the use as an n-UV-based white light-emitting diode. The powder diffraction pattern of the synthesized material confirms the formation of the triclinic phase of LiSrP3O9. Due to the 4f–4f transition of the Dy³⁺ ion, the excita...

A series of Sm³⁺ doped and Li⁺/Na⁺/ K⁺ co-doped CaSr2(PO4)2 phosphors were prepared via solution combustion synthesis. The luminescence and thermometric studies of the phosphors were investigated to explore the phosphor for potential application in high power light emitting diodes and optical thermometry. The diffraction pattern showed that the str...

The thermoluminescence (TL) response and kinetic parameters of CaMgB2O5:Tb3+ phosphor against UV-C radiations (λ = 254 nm) had been investigated. The powder X-ray diffraction results confirm the formation of the monoclinic phase. TL results depict that the glow curve exhibited a broad peak centered at 430 K. The position and the shape of the curve...

Upconverting Er³⁺–Yb³⁺ co-doped Na3Y(PO4)2 phosphors were synthesized by employing the solution combustion method for optical thermometry application. The fundamental physicochemical properties of the prepared phosphors were examined. X-ray powder diffraction analysis and field emission scanning electron microscopy had been used to characterize the...

Sr3B2O6:Tb³⁺/PMMA luminescent polymer nanocomposite (LPNC) films have been obtained by combustion synthesis of Sr3B2O6:Tb³⁺ nanophosphors (NPs) and their subsequent dispersion in a polymer (PMMA) matrix by the solution casting method. The work presented here reports the experimental investigations of such LPNC films in order to assess their viabili...

Near UV excited highly pure red light emitting Ca3B2O6:Eu3+phosphor was synthesized via a solution combustion method. The prepared samples were examined using Powder X-ray diffraction (XRD), Fourier transform infrared (FT-IR), X-ray photoelectron spectroscopy (XPS) and Photoluminescence (PL) spectroscopy for their structural, spectral, surface, and...

Highly efficient and reusable Sr4Al14O25: Eu²⁺, Dy³⁺@ZnO nanocomposites were developed for the photocatalysis of toxic pollutants from aqueous systems. The structural, photophysical and photocatalytic properties of the materials were investigated by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray, and photoluminescence spec...

Mg3(1􀀀 x)Dy3x(PO4)2 (x=0, 0.005, 0.01, 0.02, 0.03, 0.04, 0.05 and 0.06) are synthesized via solution combustion method using urea as fuel. The structure of undoped and Mg3(PO4)2:Dy3+ (2 mol. %) phosphors are confirmed by XRD and found to be a monoclinic with space group P21/n (14). The FTIR and Raman spectra confirms the presence of antisymmetric a...

The influence of an adjoining cation on the luminescence performance of the Dy³⁺ doped M3Gd(PO4)2; (M = Na, K) phosphors synthesized by solution combustion method was investigated. Structure formation, photoluminescence performance, photometric properties, and energy transfer were studied in detail. Powder X-ray diffraction patterns depict that the...

Cost-effective non-rare earth doped phosphor materials, particularly Mn⁴⁺ activated nitrides and fluorides, are emerging as prospective alternatives to rare earth doped red-emitting phosphor materials for light emitting diodes. Yet, it is challenging to prepare such cost-effective and high purity red-emitting non-rare earth doped phosphors because...

The nanopowders of LiSrVO4:Tb³⁺ phosphors with varying Tb³⁺ concentration were prepared using the combustion route. The single phase monoclinic structure with space group P12/m and crystalline nature of the powders were confirmed by the powder X-ray diffraction (XRD) technique. The agglomerated morphology of nanocrystalline grains of powders was es...

Effects of cationic substitution on the luminescence behavior of Dy³⁺ doped orthophosphate (A3B(PO4)2; A = K, Na; B = Y, La) phosphors synthesized by the solution combustion method were investigated. The powder X-ray diffraction (PXRD) and photoluminescence (PL) studies were done to examine the structural and luminescence behavior of Dy³⁺ ions in t...

A series of single doped (Eu³⁺ or Tb³⁺) and codoped (Eu³⁺ and Tb³⁺) phosphors were synthesized by solution combustion method. The single doped NaSrBO3:Tb³⁺ and NaSrBO3:Eu³⁺ emit green and red emission due to the characteristic 4f–4f transition of the Tb³⁺ and Eu³⁺ ions, respectively, under respective excitation wavelengths. Whereas, under Tb³⁺ exci...

In this work, a series of Dy3+(0.25, 0.5, 1, 1.5, 2, 2.5 mol. %) doped Mg2P2O7 phosphors were synthesized via solution combustion method. The crystal structure and phase purity of phosphor were identified by X-ray diffraction technique. The lattice parameters was obtained from Rietveld refinement and found to be a = 13.15 Å, b = 8.297 Å and c = 9.0...

Okra (Abelmoschus esculentus (L.) Moenche) is one of the warm season crops that is grown in the tropical and subtropical regions of the world. Root-knot nematodes, Meloidogyne spp. is major constraints in growing okra crops and reduce the crop yield. The present study was aimed to perform microscopic, elemental and molecular spectroscopic investiga...

Traditional medicines are one of the primary healthcares for majority of people. The color of Black turmeric (Curcuma caesia) rhizome is generally of bluish-black and has been used for its unique medicinal and religious properties. Thus in the present paper, we have performed spectroscopic investigations on rhizomes of black turmeric (Curcuma caesi...

Thermoluminescence (TL) response and kinetic parameters of Pr³⁺ doped K3La(PO4)2 phosphor under UV radiation synthesized by the combustion method had been reported. The X-ray diffraction pattern revealed a pure monoclinic phase of the K3La(PO4)2. The TL glow curves exhibited a single peak at ∼578±4 K. The TL intensity increased linearly upto 240 mi...

LiZnBO3:Sm³⁺ orange-red emitting phosphor was synthesized via solution combustion method. The crystal phase formation was confirmed via X-ray diffraction (XRD) and found to be monoclinic. The average crystalline size and lattice parameter of the material was calculated using the Debye-Scherrer formula and Bragg’s law, respectively. The optical prop...

Thermoluminescence (TL) response of trivalent dysprosium ion doped Li4Ca(BO3)2 phosphor prepared by combustion method was studied. The samples were exposed to ultraviolet (UV-C) radiation (254 nm). The orthorhombic crystal structure of the Dy³⁺ doped Li4Ca(BO3)2 nanophosphors was confirmed by X-Ray diffraction patterns. The TL glow curves showed a...

The multivariate analysis methods have recently gained high popularity within the field of forensic sciences because of their high accuracy and precision. The accurate and unbiased results are the preliminary need for a forensic investigation. The aim of the present work is to examine the marker pen inks which are widely used in various places like...

The Sm³⁺ doped KCaVO4 phosphor powders were synthesized via combustion route. The powder X-ray diffraction (pXRD) analysis established the crystalline structure and phase of the phosphor material. Williamson-Hall technique was employed to approximate the mean grain size and lattice micro-strain. The transmission electron microscope (TEM) studies we...

Herein, Dy³⁺ doped ZnAl2O4 phosphor was synthesized by the solution combustion method. The synthesized phosphor was characterized by X-ray diffraction (XRD), photoluminescence (PL) spectroscopy, UV-Vis spectroscopy and X-ray photoelectron spectroscopy (XPS). The phase purity of the phosphor was confirmed by the XRD studies that showed cubic symmetr...

Zinc Aluminate (ZnAl2O4) is a well-known wide band gap oxide that belongs to a class of mixed-metal oxides knows as spinels (AB2O4) where A and B are divalent and trivalent cations. Herein, the structural and photoluminescence properties of Sm³⁺ ion doped with ZnAl2O4 phosphors are reported. The nanophosphors were synthesized via solution combustio...

Orange-red emitting Sm³⁺ doped Li4Ca(BO3)2 phosphors synthesized by combustion method were investigated for the applications in white light-emitting diodes. The phase purity and photoluminescence performance of the Li4Ca(BO3)2:Sm³⁺ phosphor were studied in detail using the powder X-ray diffraction technique, UV-VIS-NIR absorption and Photoluminesce...

A series of Tb³⁺ doped CeF3 and NaCeF4 nanoparticles with different morphology and dimension were synthesized via hydrothermal method. Different organic additives, including sodium dodecyl sulfonate (SDS), polyvinylpyrrolidone (PVP), cetyltrimethyl ammonium bromide (CTAB), oleic acid (OA), polyethylene glycol (PEG), trisodium citrate (Cit) were int...

This work investigates the structural, optical and photometric characterization of a Eu2+/Dy3+ doped calcium aluminates phosphor (CaAl2O4: Eu2+/Dy3+) for finger and lip print detections. Synthesis of CaAl2O4: Eu2+/Dy3+ (CAED) phosphors were carried out via a combustion synthesis method with urea as a fuel. Eu2+/Dy3+ doped CaAl2O4 phosphors have bee...

A potential green emitting NaSrBO3:Tb³⁺ (1–9 mol%) phosphor was synthesized by a citrate gel combustion method. X-ray diffraction patterns confirmed the monoclinic phase of the phosphor. The phosphor emitted intense green emission under near-UV and electron excitation due to the characteristics transitions ⁵D4→⁷F6(488 nm), ⁵D4→⁷F5(544 nm), ⁵D4→⁷F4(...

The LiSrVO4:Sm³⁺ phosphor powders were synthesized by the combustion method by varying the concentration of the Sm³⁺ ions from 0.25 mol% to 2.5 mol%. The powder X-ray diffraction (XRD) studies confirmed that the phosphors were crystallized as monoclinic structure belonging to space group P2/m and the transmission electron microscopy (TEM) revealed...

The present paper reports on the structural and luminescent properties of un-doped and Sm³⁺ doped Ba2Ca(BO3)2 phosphors synthesized by the conventional solid state method. For structural characterizations, the X-ray diffraction, FTIR spectroscopy and Rietveld refinement method were used. The FTIR spectrum was composed of basic BO3 and BO4 structura...

In this paper, we report a surfactant-assisted self-sacrificing route for synthesis of Eu3+ doped LaPO4 nanostructures under hydrothermal conditions using the La(OH)CO3 : Eu3+ precursor as a template and NH4H2PO4 as the phosphate source. The synthesis was carried out in the absence and presence of surfactant [cetyltrimethyl ammonium bromide (CTAB)]...

In this work, white light emitting α-Al 2 O 3 : xDy 3+ (x = 0.5-2.5 mol. %) phosphors, were synthesized by the solution combustion method at 550 C. X-ray diffraction (XRD) and photoluminescence (PL) spectroscopy techniques were used to study the structural and spectral properties of the phosphors. XRD studies confirm the hexagonal structure of the...

The LiSr(1−3/2x)VO4:xSm³⁺ (0.0025 ≤ x ≤ 0.03) phosphors were prepared by the low cost combustion method. The structural and luminescence studies were carried out with powder X-ray diffraction, transmission electron microscopy, photoluminescence spectroscopy and diffuse reflectance spectroscopy (DRS) characterization techniques. The nanosized phosph...

In this research, we characterized and discriminated 24 different kinds of writing/printing papers that may or may not have similar compositions by using Thermogravimetric Analysis (TGA). All paper samples were obtained from the local market in and around Chandigarh (Northwestern part of India). Large differences were observed on the estimation of...

Evaluation of thermoluminescence (TL) properties of γ-ray and heavy ion (120 MeV Ag9+) exposed NaSrBO3:Sm3+ phosphor prepared by solution combustion (SC) method was done and the results were compared to its counterpart prepared by solid state (SS) method. The TL study was carried out after exposing the samples to γ-radiation and swift heavy ion (SH...

A near UV-light downconvertible narrow-band red emitting europium (0.5–7 mol. %) doped strontium orthovanadate nanophosphors were synthesized by a combustion method taking urea as fuel. For charge compensation, the material was also co-doped with alkali metal ions (Li⁺, Na⁺, K⁺). Powder X-ray diffraction results revealed that the material was in rh...

This paper reports the surface, spectral and luminescent properties of Dy³⁺ doped CaMgB2O5 phosphor synthesized by combustion method. X-ray diffraction (XRD) was used to characterize the phase structure. X-ray photoelectron spectroscopy (XPS) was used to investigate the surface elemental composition and chemical states of the synthesized phosphor....

α-Al2O3 powder is synthesized by a simple combustion method. The powder was characterized by using X-ray diffraction (XRD) and transmission electron microscopy (TEM). XRD results confirmed the complete formation of α-Al2O3 phase at temperature 550 °C. Microstructure study shows that the particles have spherical like shape and their average size is...

Li4Ca1-xB2O6:xDy3+ (x = 0.5—2.5 mol%) nanocrystalline phosphors are prepared by combustion synthesis involving mixtures of Ca(NO3)2, LiNO3, Dy2O3, and NH2CONH2 as the fuel together with 2.5 wt% PEG as dispersant (1.

The present study was aimed at analyzing uninfected wheat grain (Triticum aestivum) and wheat seed gall nematodes (Anguina titici) by means of wave-dispersive X-ray fluorescence (WD-XRF), Fourier transform infra-red (FTIR) spectroscopy and Diffuse reflectance spectroscopy to assess their elemental and molecular compositions. WD-XRF was used to dete...

Molecular structure, harmonic vibrational frequencies, Mulliken charges and temperature dependence of thermodynamic properties of bilirubin molecule have been investigated by Density Functional Theory (DFT) using standard B3LYP/6-311G basis set in the ground state. The Fourier Transform Infra-red (FTIR) spectrum of bilirubin in the spectral region...

Trivalent dysprosium (Dy3+) ion activated NaSrBO3 phosphor was synthesized by conventional solid state method and its thermoluminescence response against γ-ray and heavy ion (120 MeV Ag9+) exposure was investigated. The investigations were done in the range of 0.01–5 kGy and 1 × 1011–1 × 1013 ions cm−2 for γ-ray and heavy ions, respectively. The gl...

Thermoluminescence(TL) response of LiMgBO3:Dy3+ nanophosphor synthesized by combustion method was examined using γ-ray and 120 MeV Ag9+ swift heavy ion (SHI) irradiation. The LiMgBO3:Dy3+ samples were exposed to 0.01 kGy −5 kGy γ-rays while for the different fluences the samples were irradiated with 120 MeV Ag9+ SHI over the range 1×1011 ions cm−2...

Undoped and trivalent samarium (0.5–2.5 mol%) doped K3Gd(PO4)2 phosphors were synthesized by solid state method (SSM), combustion method (CM) and citrate gel combustion method (CGCM), respectively. The resulting phosphors were characterized by X-ray diffraction (XRD), diffuse reflectance spectroscopy (DRS) and photoluminescence (PL) spectroscopy. T...

α-Al2O3 powder sample was synthesized at 550 °C via solution combustion synthesis (SCS) method using urea as an organic fuel. The sample was characterized by X-ray diffraction (XRD), Optical spectroscopy and X-ray photoelectron spectroscopy (XPS) without any further thermal treatment. XRD study reveals that the powder crystallized directly in the h...

In this paper, thermoluminescence (TL) properties of Dy3+ (1.5 mol %) doped CaMgB2O5 nanophosphor after being exposed to ultraviolet (UV) radiations (λ=254nm) were investigated. In UV exposed samples, the thermoluminescence glow curve consists of a broad glow peak located at 380 K with a small shoulder at 507 K. A shift in glow peak temperature fro...

The samarium doped NaCaVO4 phosphor was synthesized by the combustion method. The X-ray powder diffraction (XRD) analysis confirmed that the phosphor powder crystallized as orthorhombic structure belonging to space group Cmcm. From Williamson-Hall analysis the grain size and microstrain in the powder was estimated. The Fouriertransform infrared (FT...

Laser-induced breakdown spectroscopy (LIBS) is an emerging analytical technique with numerous advantages such as rapidity, multi-elemental analysis, no specific sample preparation requirements, non-destructiveness, and versatility. It has been proven to be a robust elemental analysis tool attracting interest because of being applied to a wide range...

The relaxation behavior of gelatin aqueous solutions has been investigated by time resolved dynamic light scattering (TRDLS) measurements at different temperatures spanning the entire sol to gel phase transition behavior of the system (i.e. from 5 min to 1440 min after a sudden quench from high temperature sol to low temperature gel state), when th...

In this work, europium and dysprosium doped strontium aluminate (SrAl2O4:Eu2+,Dy3+) nanophosphor is synthesized and its novel application for the detection of latent fingerprints on various contact surfaces is reported. The SrAl2O4:Eu2+,Dy3+ is synthesized using a combustion method and shows long-lasting afterglow luminescence. The powder particles...

In this paper, we report the synthesis of trivalent Tb3+ doped Sr3B2O6 phosphor by combustion method using urea as an organic fuel. The structure of the product has been verified by X-ray diffraction study which shows a rhombohedral phase with a space group of R-3c having lattice constants a = 9.064 Å, b = 9.064 Å, c = 12.611 Å. X-ray photoelectron...

Dy3+ doped Ca3B2O6 phosphors were synthesized by combustion method at 600 °C, using urea as fuel, and their surface, spectral, photoluminescence (PL) and thermoluminescence (TL) properties were investigated. The structural properties of the phosphor were examined by the powder X-ray diffraction method after annealing the phosphor at 900 °C for 3 h....

In the present work, we have presented a combined experimental and Density Functional Theory (DFT) computational studies on curcumin molecule which is a bio-active ingredient of Rhizome turmeric to describe its molecular structure, complete vibrational spectra, electronic transition and thermal stability of the compound. We have characterized the t...

Orange-red emitting Pr3+ doped NaSrBO3 nanophosphors were synthesized through a combustion process using metal nitrates as precursors and urea as fuel. Structural, optical and luminescence properties of the phosphors were investigated by using powder X-ray diffraction, diffuse reflectance (DR) spectroscopy and photoluminescence (PL) spectroscopy, r...

A series of CaMgB2O5 phosphors co-doped with Sm3+ and alkali metal ions (Li+, Na+ and K+) were prepared by combustion method. The crystal structure of the phosphors was investigated by using X-ray diffraction (XRD) after annealing the phosphor at 900 °C. The crystal structure belongs to the monoclinic phase of CaMgB2O5with space group P21/b. FTIR s...

The structural and luminescent properties of Sm3+ doped NaSrVO4 phosphors prepared by the combustion method were investigated. The phosphors were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), photoluminescence spectroscopy (PL) and diffuse reflectance spectroscopy (DRS). NaSrVO4 crystallized into the monoc...

For the first time, spatial distribution of major and trace elements has been studied in cholesterol gallstones using time-of-flight secondary mass ion mass spectrometry (TOF-SIMS). The TOF-SIMS has been used to study the elemental constituents of the center and surface parts of the gallstone sample. We have classified the gallstone sample using Fo...