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Indian Journal of Pure & Applied Physics (IJPAP) >
IJPAP Vol.48 [2010] >
IJPAP Vol.48(12) [December 2010] >
| Title: | Characterization, dielectric and optical studies of cerium molybdo tungstate nanoparticles |
| Authors: | Indulal, C R
Kumar, G Sajeev
Vaidyan, A V
Raveendran, R |
| Keywords: | Nano particles
XRD
TEM
AFM
Optical band gap
Dielectric permittivity |
| Issue Date: | Dec-2010 |
| Publisher: | NISCAIR-CSIR, India |
| Abstract: | Nanoparticles of
cerium molybdo tungstate (CMT) have been prepared by chemical co-precipitation
method. The average particle size is determined from X-ray diffraction studies.
The nanoparticle nature of the sample is verified using SEM, TEM and AFM
images. The surface morphology of the sample is studied from SEM image. The
FTIR spectrum has been used to study the stretching and bending frequencies of
molecular groups in the sample. Temperature and frequency dependence of the
dielectric constant and ac electrical
conductivity have been investigated. The dielectric permittivities of the
samples are evaluated from the observed capacitance values in the frequency
range 100 Hz-1 MHz and in the temperature range 50°-110°C. It has been found that with
increasing frequency, the dielectric constant decreases. The high value of
dielectric constant at low frequencies may mainly be due to the space charge
and rotational polarization. Also, the dielectric constant increases with
increase in temperature for fixed frequencies. As the temperature increases
more and more dipoles will be oriented resulting in an increase in molecular
dipole moment. The ac electrical
conductivity is evaluated from the permittivity studies. The absorption spectra
of the sample in the UV range are recorded. From the analysis of the absorption
spectra, the material is found to have a direct band gap of 3.2 eV. |
| Page(s): | 893-898 |
| CC License: |  CC Attribution-Noncommercial-No Derivative Works 2.5 India |
| ISSN: | 0975-1041 (Online); 0019-5596 (Print) |
| Source: | IJPAP Vol.48(12) [December 2010]
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