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Author Gul, Muhammad
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword MATERIALS SCIENCE ♦ NANOSCIENCE AND NANOTECHNOLOGY ♦ CHARGE CARRIERS ♦ CHROMITES ♦ COPRECIPITATION ♦ CRYSTAL STRUCTURE ♦ CRYSTALS ♦ DIELECTRIC MATERIALS ♦ FOURIER TRANSFORMATION ♦ INFRARED SPECTRA ♦ MANGANESE COMPOUNDS ♦ NANOPARTICLES ♦ NANOSTRUCTURES ♦ PARTICLE SIZE ♦ PERFORMANCE ♦ PERMITTIVITY ♦ POLARONS ♦ RADIOWAVE RADIATION ♦ SPACE CHARGE ♦ SURFACTANTS ♦ X-RAY DIFFRACTION
Abstract Highlights: • Uniform MnCr{sub 2}O{sub 4} nanoparticles synthesized by surfactant-free coprecipitation route. • XRD analysis confirmed the single spinel phase formation in the material. • Dielectric loss was found abnormal over certain lower frequencies. • AC conductivity proved the involvement of small polarons in conduction process. - Abstract: Radio frequency dielectric behavior of nanocrystalline MnCr{sub 2}O{sub 4} synthesized via surfactant-free controlled coprecipitation route has been studied. Keeping in view the necessity of particle size uniformity and phase purity for genuine performance, experimental conditions were optimized accordingly. The scanning electron micrographs of the synthesized product revealed the formation of monodispersed particle system. X-ray diffraction analysis confirmed monophasic spinel structure formation with 65 nm crystallite size. Two characteristic peaks observed between 700 cm{sup −1} and 400 cm{sup −1} in the FTIR spectrum also supported the spinel phase purity of compound. The dielectric constant was found normal, but loss tangent of the sample showed abnormal behavior with frequency. The observed dielectric behavior of the synthesized product has been explained on the basis of space-charge polarization according to Maxwell–Wagner’s model and mutual contribution of n-type &p-type charge carriers (Rezlescu model). The ac conductivity linearly increased with frequency highlighting the existence of polaron hopping.
ISSN 00255408
Educational Use Research
Learning Resource Type Article
Publisher Date 2016-04-15
Publisher Place United States
Journal Materials Research Bulletin
Volume Number 76


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