화학공학소재연구정보센터
Journal of Materials Science, Vol.29, No.15, 4001-4006, 1994
Fecl3 Doped Polyvinylidene Fluoride .2. Pauli Susceptibility and Microwave Response
Magnetic susceptibility measurements of FeCl3 doped polyvinylidene fluoride (PVDF) films over the dopant mass fraction range 0 less-than-or-equal-to W less-than-or-equal-to 0.45 (wt%) and the temperature, T, range 85-300 K are presented. Undoped PVDF exhibited temperature independent Pauli paramagnetic (TIPP) susceptibility at 150 less-than-or-equal-to T less-than-or-equal-to 300 K, which was followed by an antiferromagnetic Neel peak at T(N) = 120 K. In the case of doped PVDF, TIPP susceptibility was followed by a Curie-Wiss temperature dependence with a positive paramagnetic Curie point, indicating ferromagnetic interaction at lower temperatures. The onset of TIPP was attributed to one-dimensional magnetic interaction of itinerant states close to the Fermi surface. It is implied that the [C2H2F2(FeCl4)y(FeCl2)yClz]x complex was formed by doping. A chlorination model was proposed to calculate the stoichiometric coefficients y and z, using magnetic susceptibility data. The microwave response of the doped PVDF has been examined. It is found that changing the doping level results in composites of different reflection coefficient phase and power reflection factors.