Dielectric and conductivity studies on cobalt phthalocyanine tetramers

Electrically conductive organic and metalloorganic polymers are of great interest and they have applications in electronic, optical, photonic, photoelectric, electrochemical, and dielectric devices. Tetrameric cobalt phthalocyanine was prepared by conventional chemical method. The dielectric permittivity of the tetrameric cobalt phthalocyanine sample was evaluated from the observed capacitance values in the frequency range 100 KHz to 5 MHz and in the temperature range of 300 to 383degreesK. It is found that the system obeys the Maxwell Wagner relaxation of space charge phenomenon. Further, from the permittivity studies AC conductivity was evaluated. The values of AC conductivity and DC conductivity were compared. Activation energy was calculated. To understand the conduction mechanism Mott's variable range hopping model was applied to the system. The T-1/4 behavior of the DC conductivity along with the values of Mott's Temperature (T-0), density of states at the Fermi energy N (E-F), and range of hopping R and hopping energy W indicate that the transport of charge carriers are by three-dimensional variable range hopping. (C) 2003 Wiley Periodicals, Inc.