Dielectric behaviour of pure and nickel-doped cellulose acetate films

✍ Scribed by Veeravazhuthi, V.; Narayandass, Sa. K.; Mangalaraj, D.

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 265 KB
• Volume: 45
• Category: Article
• ISSN: 0959-8103
• DOI: 10.1002/(sici)1097-0126(199804)45:4<383::aid-pi949>3.0.co;2-t

✦ Synopsis

Pure and Ni (0É05%, 0É1% and 0É15%)-doped cellulose acetate (CA) Ðlms were formed on well-cleaned glass substrates using a solution growth technique. MetalÈinsulatorÈmetal (MIM) sandwich structures of thin Ðlm capacitors were fabricated. Dielectric studies were carried out in the frequency range 1 kHHz to 10 MHz in the temperature range 303È450 K. The variation of capacitance and dielectric loss with temperature were studied at various frequencies. The variation of dielectric constants (e@ and eA) with frequency and temperature is discussed. An increase in capacitance with temperature was observed and this may be due to the chaotic oscillations of molecules in the polymer matrix. b (at lower temperature) and a (at higher temperature) relaxation loss peaks were observed. Doping results in the formation of charge transfer complexes/ molecular aggregates in the polymer, which cause the shift of value and the C max b and a relaxation loss peaks towards higher temperature. An appreciable dispersion of tan d at lower frequency was noticed in all the samples studied. 1998 ( SCI.