skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Effect of mixing Ce{sup 3+} and Nd{sup 3+} ions in equimolar ratio on structural, optical and dielectric properties on pure cerium orthovanadate and neodymium orthovanadate

Abstract

Highlights: • CeV, NdV and mixed CeNdV nanoparticle prepared by chemical co precipitation method. • With mixing of Ce{sup 3+} and Nd{sup 3+} morphology is totally changed in mixed CeNdV. • Optical band energy of CeV, NdV and CeNdV shows good photocatalyst under UV light. • Conduction mechanism in CeV due to large polaron and small polaron in CeNdV. - Abstract: Cerium orthovanadate, neodymium orthovanadate and mixed cerium neodymium orthovanadate nanoparticles was prepared by co-precipitation method. Powder X-ray diffraction reveals tetragonal zircon structure. Slight increase in lattice parameter, volume and decrease in X-ray density inferred that Ce{sup 3+} and Nd{sup 3+} ion replaces each other. Transmission electron microscopy suggests change in morphology with the effect of mixing and validates formation of nanocrystalline material. The infrared transmittance spectrum confirmed the presence of various functional groups. Dielectric properties as function of frequency show dielectric constant and loss tangent decreases with increase in frequency which is due to Maxwell–Wagner type interfacial polarization. The variation of AC conductivity measurement with frequency suggests conduction mechanism due to large polaron hopping in CeV whereas small polaron in mixed CeNdV. The activation energy decreases with rising frequency indicates the conduction mechanism is based on polaron hopping betweenmore » localized states in disordered manner.« less

Authors:
; ;
Publication Date:
OSTI Identifier:
22581622
Resource Type:
Journal Article
Resource Relation:
Journal Name: Materials Research Bulletin; Journal Volume: 81; Other Information: Copyright (c) 2016 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ACTIVATION ENERGY; CERIUM COMPOUNDS; CERIUM IONS; COPRECIPITATION; DIELECTRIC MATERIALS; FREQUENCY DEPENDENCE; INFRARED SPECTRA; LATTICE PARAMETERS; MORPHOLOGY; NANOPARTICLES; NANOSTRUCTURES; NEODYMIUM COMPOUNDS; NEODYMIUM IONS; PERMITTIVITY; POLARONS; TETRAGONAL LATTICES; TRANSMISSION ELECTRON MICROSCOPY; ULTRAVIOLET RADIATION; VANADATES; X-RAY DIFFRACTION

Citation Formats

Verma, Seema, Gupta, Rashmi, and Bamzai, K.K., E-mail: kkbamz@yahoo.com. Effect of mixing Ce{sup 3+} and Nd{sup 3+} ions in equimolar ratio on structural, optical and dielectric properties on pure cerium orthovanadate and neodymium orthovanadate. United States: N. p., 2016. Web. doi:10.1016/J.MATERRESBULL.2016.05.003.
Verma, Seema, Gupta, Rashmi, & Bamzai, K.K., E-mail: kkbamz@yahoo.com. Effect of mixing Ce{sup 3+} and Nd{sup 3+} ions in equimolar ratio on structural, optical and dielectric properties on pure cerium orthovanadate and neodymium orthovanadate. United States. doi:10.1016/J.MATERRESBULL.2016.05.003.
Verma, Seema, Gupta, Rashmi, and Bamzai, K.K., E-mail: kkbamz@yahoo.com. 2016. "Effect of mixing Ce{sup 3+} and Nd{sup 3+} ions in equimolar ratio on structural, optical and dielectric properties on pure cerium orthovanadate and neodymium orthovanadate". United States. doi:10.1016/J.MATERRESBULL.2016.05.003.
@article{osti_22581622,
title = {Effect of mixing Ce{sup 3+} and Nd{sup 3+} ions in equimolar ratio on structural, optical and dielectric properties on pure cerium orthovanadate and neodymium orthovanadate},
author = {Verma, Seema and Gupta, Rashmi and Bamzai, K.K., E-mail: kkbamz@yahoo.com},
abstractNote = {Highlights: • CeV, NdV and mixed CeNdV nanoparticle prepared by chemical co precipitation method. • With mixing of Ce{sup 3+} and Nd{sup 3+} morphology is totally changed in mixed CeNdV. • Optical band energy of CeV, NdV and CeNdV shows good photocatalyst under UV light. • Conduction mechanism in CeV due to large polaron and small polaron in CeNdV. - Abstract: Cerium orthovanadate, neodymium orthovanadate and mixed cerium neodymium orthovanadate nanoparticles was prepared by co-precipitation method. Powder X-ray diffraction reveals tetragonal zircon structure. Slight increase in lattice parameter, volume and decrease in X-ray density inferred that Ce{sup 3+} and Nd{sup 3+} ion replaces each other. Transmission electron microscopy suggests change in morphology with the effect of mixing and validates formation of nanocrystalline material. The infrared transmittance spectrum confirmed the presence of various functional groups. Dielectric properties as function of frequency show dielectric constant and loss tangent decreases with increase in frequency which is due to Maxwell–Wagner type interfacial polarization. The variation of AC conductivity measurement with frequency suggests conduction mechanism due to large polaron hopping in CeV whereas small polaron in mixed CeNdV. The activation energy decreases with rising frequency indicates the conduction mechanism is based on polaron hopping between localized states in disordered manner.},
doi = {10.1016/J.MATERRESBULL.2016.05.003},
journal = {Materials Research Bulletin},
number = ,
volume = 81,
place = {United States},
year = 2016,
month = 9
}
  • Polycrystalline Bi{sub 2}Fe{sub 4}O{sub 9} and 2% Co doped Bi{sub 2}Fe{sub 4}O{sub 9} were prepared by solid state reaction route. X-ray diffraction (XRD) result reveals that there is no change in the crystal structure due to Co doping and the compound has orthorhombic structure. UV-visible spectroscopy confirms the decrease in band gap due Co doping. Zero field cooled magnetization measurement at 100 Oe magnetic field shows substantial decrease in the magnetic transition temperature. Room temperature frequency dependent dielectric permittivity at 1V DC bias shows ∼10% increase in Co doped sample with respect to pure Bi{sub 2}Fe{sub 4}O{sub 9}.
  • A diluted magnetic semiconductor (DMS) Co-doped TiO{sub 2} is studied here for dielectric properties. Undoped and Co-doped TiO{sub 2} samples were prepared by sol-gel method. The formation of anatase phase has been investigated by X-ray diffraction (XRD). UV-Vis absorption spectra show that the incorporation of Co into the TiO{sub 2} lattice leads to redshift in the optical response, as well as lowering the band gap energy. The defect oriented emissions were seen from photoluminescence (PL) study. The dielectric properties of pure and Co-doped TiO{sub 2} samples were studied in the frequency range of 10 Hz to 10 MHz at different temperatures. Dopedmore » sample exhibit low dielectric constant when compared with host system. Both dielectric constant and ac conductivity increases with temperature.« less
  • A detailed structural analysis and dielectric property measurements of silicon nitride films fabricated using atmospheric pressure (AP) plasma were carried out, and the results were compared to those of nitride films fabricated using a radio frequency plasma. Using AP plasma, 1.8-nm-thick silicon nitride films composed of Si{sub 3}N{sub 3.5}O{sub 0.7} were obtained at nitridation temperatures ranging from 25 to 500 deg. C. X-ray photoelectron spectroscopy using a monochromatic Al K{alpha} source at 1486.6 eV and high-resolution Rutherford backscattering spectrometry revealed approximately 10% more nitrogen atoms corresponding to the N-Si{sub 3} bond in the film using AP plasma than those usingmore » rf plasma. In the range of 25-500 deg. C, the nitridation temperature did not affect the leakage current densities of the films fabricated using AP plasma. Films fabricated at 25 deg. C showed leakage current density of as low as 7x10{sup -2} A/cm{sup 2} at 5 MV/cm. This value was one order of magnitude lower than that using rf plasma. The direct-tunneling current simulation analysis with the Wentzel-Kramers-Brillouin approximation revealed that the effective tunneling mass of holes increased due to the nitrogen atoms incorporated in the films. From deep-level transient spectroscopy, signals attributed to defects generated by plasma irradiation in the silicon substrate were not observed.« less