Author/Authors :
Cruz، نويسنده , , Ana M.M. and Borges، نويسنده , , R.P. and Godinho، نويسنده , , M. and Marques، نويسنده , , C.S. and Langa، نويسنده , , E. R. Ribeiro and I. Barbi، نويسنده , , A.P.C. and Lourenço، نويسنده , , M.J.V. and Santos، نويسنده , , F.J.V. and Nieto de Castro، نويسنده , , C.A. and Macatrمo، نويسنده , , M. Abu Tariq، نويسنده , , Isabel M. and Esperança، نويسنده , , J.M.S.S. and Canongia Lopes، نويسنده , , J.N. and Afonso، نويسنده , , C، نويسنده ,
Abstract :
The density, heat capacity and viscosity of two magnetic ionic liquids sharing the same Fe (III)-containing anion, specifically, [C4mim][FeCl4] and [P6 6 6 14][FeCl4], have been determined, along with their volumetric expansivity, and thermal decomposition temperatures. The magnetic properties of the two compounds have been studied using SQUID magnetometry. Both [C4mim][FeCl4] and [P6 6 6 14][FeCl4] are paramagnetic, but while in the first case the magnetic moment value is 5.8 μB/Fe, therefore close to that of Fe3+, for the latter it is only 4.8 μB/Fe. The effective concentration of magnetic sites is almost three times greater for [C4mim][FeCl4] as compared to [P6 6 6 14][FeCl4]. In this latter case, the experimental isothermal magnetization curves do not follow a Brillouin-type of behavior; alternatively, the results were discussed using the Spin Hamiltonian formalism in terms of both the distortion of the Iron site and covalence effects.
Keywords :
Volumetric expansivity , heat capacity , magnetic moment , paramagnetism , VISCOSITY , Decomposition temperature , Density
