NANOSYSTEMS: PHYSICS, CHEMISTRY, MATHEMATICS, 2016, 7 (4), P. 599–603
Dielectric studies of nanocrystalline calcium tungstate
N. Aloysius – Department of Physics, Newman College Thodupuzha-685 585, Kerala, India (Affiliated to M. G. University, Kottayam); firstname.lastname@example.org
M. S. Rintu – Department of Physics, Maharajas College, Ernakulam-682 011, Kerala, India
E. M. Muhammed – Department of Physics, Maharajas College, Ernakulam-682 011, Kerala, India
T. Varghese – Department of Physics, Newman College Thodupuzha-685 585, Kerala, India (Affiliated to M. G. University, Kottayam); Nanoscience Research Centre (NSRC), Department of Physics, Nirmala College, Muvattupuzha – 686 661, Kerala, India
Nanocrystalline samples of CaWO4 were prepared at room temperature by simple chemical precipitation. The samples were characterized by X-ray diffraction and scanning electron microscopy. Energy dispersive X-ray analysis confirmed the elements present in the sample. The frequency and temperature dependence of the dielectric constant and ac electrical conductivity of the nanomaterial were investigated. Very low dielectric loss in nanocrystalline CaWO4 powder was observed at high frequencies. The values of ac electrical conductivity calculated from the permittivity studies were found to increase as frequency increased, conforming to small polaron hopping.
Keywords: Chemical precipitation, dielectric constant, ac electrical conductivity, polaron hopping.
PACS 78.67.Bf, 81.16.Be, 73.63.b