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Title: Thermal analysis and temperature dependent dielectric responses of Co doped anatase TiO{sub 2} nanoparticles

Nanoparticles (NPs) of pure and 5 mol % cobalt doped TiO{sub 2} synthesized through acid modified sol-gel method were characterized to understand their thermal, structural, morphological, and temperature dependent dielectric properties. Thermogravimetric analysis (TGA) has been used for thermal studies and indicates the weight loss in two steps due to the removal of residual organics. X-ray diffraction study was employed to confirm the formation of single anatase phase with tetragonal symmetry for both pure and 5 mol % Co doped TiO{sub 2} NPs. The average crystallite size of both samples was calculated from the Scherrer’s formula and was found in the range from 9-11 nm. TEM micrographs of these NPs reflect their shape and distribution. The dielectric constant (ε′), dielectric loss (tanδ) and ac conductivity (σ{sub ac}) were also studied as a function of temperature at different frequencies. Electrical responses of the synthesized NPs have been analyzed carefully in the framework of relevant models. It is also noticed that the dielectric constant (ε′) of the samples found to decrease with increasing frequency but increases with increasing temperature up to a particular value and then sharply decreases. Temperature variation of dielectric constant exhibits step like escalation and shows relaxation behavior. Study of dielectric propertiesmore » shows dominant dependence on the grain size as well as Co ion incorporation in TiO{sub 2}.« less
Authors:
 [1] ;  [2] ; ; ;  [3] ;  [1]
  1. Department of Physics, Aligarh Muslim University, Aligarh-202002 (India)
  2. (Nanomaterials), Department of Applied Physics, Z.H. College of Engineering and Technology, Aligarh Muslim University, Aligarh-202002 (India)
  3. Centre of Excellence in Materials Science (Nanomaterials), Department of Applied Physics, Z.H. College of Engineering and Technology, Aligarh Muslim University, Aligarh-202002 (India)
Publication Date:
OSTI Identifier:
22391714
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1661; Journal Issue: 1; Conference: ICCMP 2014: International Conference on Condensed Matter Physics 2014, Shimla (India), 4-6 Nov 2014; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
77 NANOSCIENCE AND NANOTECHNOLOGY; COBALT; COBALT IONS; DIELECTRIC MATERIALS; DOPED MATERIALS; ELECTRIC CONDUCTIVITY; GRAIN SIZE; NANOPARTICLES; PERMITTIVITY; RELAXATION LOSSES; SOL-GEL PROCESS; TEMPERATURE DEPENDENCE; THERMAL GRAVIMETRIC ANALYSIS; TITANIUM OXIDES; TRANSMISSION ELECTRON MICROSCOPY; X-RAY DIFFRACTION