Luminescence Studies on Pr3+& Yb3+ Doped Cadmium Calcium Pyrophosphate Nanophosphors

The Cadmium Calcium Pyrophosphate doped with Pr3+ and Yb3+ was prepared by solution combustion synthesis. The luminescence studies and chromatic properties of the prepared sample were examined in the present study. The luminescence spectra of CdCaP: Pr3+ shows relevant peaks with emission at 599nm upon excitation of 445nm, whereas CdCaP: Yb3+ shows a peak at 536nm when excited with 254nm. The CIE 1931 chromaticity color coordinates for CdCaP: Pr3+ & CdCaP: Yb3+ were located in orange and greenish-yellow regions respectively. CCT and color purity values of the prepared samples were evaluated using McCam empirical formula and respective equation of color purity. Color Rendering Index (CRI) values of the prepared samples were calculated using the color calculator. © 2020 Author(s).Authors are thankful to UGC-DRS & DST-FIST, New Delhi for financial assistance to the department of physics, Acharya Nagarjuna University. One of the authors, Sk. Munimasthani expresses sincere thanks to UGC for providing financial support through MANF scheme (No. F1-17.1/2017-18/MANF-2017-18-AND-79002) to carry out the research work

Investigation on Synthesis, Structural and Optical Properties of CDS Nanoparticles

Hexagonal wurtzite structured CdS nanoparticles were synthesized by using a chemical precipitation method. Various spectroscopic technics were used for the characterization of the prepared sample. The X-ray diffraction pattern shows the high intense crystalline peaks and the average crystallite size is found to be 19nm. FT-IR spectrum exhibited a metal sulfide band at 615cm-1 and other functional groups. SEM micrographs reveal the non-uniformly distributed spherical shaped structures. EDS analysis confirms the stoichiometric composition and presence of target elements. The optical absorption spectrum exhibited a broad peak at 510nm, which indicates the shifting of the absorption rage of CdS nanoparticles into the visible region. PL spectrum exhibited the characteristic emission bands in visible region. © 2020 Author(s).One of the authors Dr. G. Thirumala Rao would like to thank the GMR Institute of Technology, Rajam for providing financial support to carry out the research work. Authors would also like to thank the Department of Physics, Acharya Nagarjuna University, Guntur

Structural Properties of Co2+ Ion Doped Calcium Cadmium Phosphate Hydrate Nanophosphor

Inorganic nanophosphor materials have captivated the worldwide attention into the field of solid-state lighting emission displays, plasma display panels, light-emitting diodes, IR quantum counters, scintillation, etc. Nanotechnology is the foremost superior in the development of phosphors with definite size and shape. Alkali and alkaline earth phosphates are promising candidates for the inorganic phosphor materials. Manufacturing of nano-inorganic materials gained much interest due to their advance lighting applications. In this work, novel Co2+ doped Calcium Cadmium Phosphate hydrate nanophosphor (CaCdPH: Co2+) was synthesized by a traditional solid-state reaction technique. The synthesized sample was characterized by Powder XRD, SEM equipped with EDX and FTIR techniques. The hexagonal phase of the prepared CaCdPH: Co2+sample was confirmed by X-ray diffraction results, and the average crystallite size was evaluated. FTIR demonstrated the formation of vibrational modes ascribed to phosphate molecules and other hydroxyl groups. The morphologies of the CaCdPH: Co2+ nanophosphor was investigated by scanning electron microscopy. © 2020 Author(s).One of the authors, T. Rajyalakshmi is thankful to JNTU Kakinada, DIC for financial assistance in the MHRD project. Authors express their special thanks to UGC-DRS, DST-FIST - New Delhi for providing financial assistance to the Dept. of Physics, Acharya Nagarjuna University. And also acknowledge the service render by scientific officers of Kerala University and Yogi Vemana University for their help providing XRD and SEM instruments for sample recordings

Luminescence studies on Pr3+& Yb3+doped cadmium calcium pyrophosphate nanophosphors

The Cadmium Calcium Pyrophosphate doped with Pr3+ and Yb3+ was prepared by solution combustion synthesis. The luminescence studies and chromatic properties of the prepared sample were examined in the present study. The luminescence spectra of CdCaP: Pr3+ shows relevant peaks with emission at 599nm upon excitation of 445nm, whereas CdCaP: Yb3+ shows a peak at 536nm when excited with 254nm. The CIE 1931 chromaticity color coordinates for CdCaP: Pr3+ & CdCaP: Yb3+ were located in orange and greenish-yellow regions respectively. CCT and color purity values of the prepared samples were evaluated using McCam empirical formula and respective equation of color purity. Color Rendering Index (CRI) values of the prepared samples were calculated using the color calculator. © 2020 Author(s).Authors are thankful to UGC-DRS & DST-FIST, New Delhi for financial assistance to the department of physics, Acharya Nagarjuna University. One of the authors, Sk. Munimasthani expresses sincere thanks to UGC for providing financial support through MANF scheme (No. F1-17.1/2017-18/MANF-2017-18-AND-79002) to carry out the research work

Synthesis of Co2+ Doped ZnO–CdS Composite Nanopowder and Its Enhanced Photocatalytic Performance under Visible Light Irradiation

Semiconductor composite nanomaterials open up new opportunities in the field of photocatalysis and have an enormous impact on the energy and environmental sectors. In the present study, an advanced catalyst, Co2+ doped ZnO- CdS composite nanopowder was prepared by using chemical precipitation method. The photocatalytic activity was observed on the degradation of methylene blue (MB). The synthesized material was characterized by powder XRD, SEM, TEM and FT-IR techniques. X-ray diffraction pattern revealed the hexagonal phase of ZnO and CdS with the lattice cell parameters in the order of nano scale. SEM and TEM micrographs shows spherical like structures with little agglomeration. FT-IR spectrum exhibited the fundamental vibrational modes of ZnO, CdS and other functional groups. Further, a plausible mechanism for the enhanced photocatalytic properties of the Co2+ doped ZnO-CdS nanocomposite has been discussed. This work on the development of ZnO-based semiconductor photocatalysis can offer new understandings into the design of novel hybrid photocatalysts for potential applications in the environmental remediation sectors. © 2019 Author(s)

Hydrothermal synthesis of ZnO nanopowder and its photocatalytic performance under UV and visible light irradiation

ZnO nanopowder was synthesized by hydrothermal method and characterized by different spectroscopic techniques. X-ray diffraction measurements reveal the hexagonal wurtzite structure of ZnO and the average crystallite size is evaluated as 34 nm. Morphological and chemical compositional details were investigated by SEM, TEM and EDS analysis. Optical absorption spectrum exhibited a characteristic exciton absorption band at 363 nm. PL spectrum exhibited various bands in UV and visible regions. FT-IR spectrum exhibited the characteristic ZnO and other functional groups. Visible light driven photocatalytic degradation of methylene blue (MB) dye in water was used to evaluate the photocatalytic performance of the prepared ZnO nanopowder. © 2019 Author(s)

Hydrothermal Synthesis of ZnO Nanopowder and Its Photocatalytic Performance under UV and Visible Light Irradiation

ZnO nanopowder was synthesized by hydrothermal method and characterized by different spectroscopic techniques. X-ray diffraction measurements reveal the hexagonal wurtzite structure of ZnO and the average crystallite size is evaluated as 34 nm. Morphological and chemical compositional details were investigated by SEM, TEM and EDS analysis. Optical absorption spectrum exhibited a characteristic exciton absorption band at 363 nm. PL spectrum exhibited various bands in UV and visible regions. FT-IR spectrum exhibited the characteristic ZnO and other functional groups. Visible light driven photocatalytic degradation of methylene blue (MB) dye in water was used to evaluate the photocatalytic performance of the prepared ZnO nanopowder. © 2019 Author(s)

Reentrant Peak Effect in an anisotropic superconductor 2H-NbSe_2 : Role of disorder

The reentrant nature of Peak Effect is established in a single crystal of 2H-NbSe_2 via electrical transport and dc magnetisation studies. The role of disorder on the reentrant branch of PE has been examined in three single crystals with varying levels of quenched random disorder. Increasing disorder presumably shrinks the (H,T) parameter space over which vortex array retains spatial order. Although, the upper branch of the PE curve is somewhat robust, the lower reentrant branch of the same curve is strongly affected by disorder.Comment: 5 Pages of text, 4 figure