Resumo

GUTIERREZ, M. P.  e  MONTIEL, H.. Propiedades dieléctricas del nitroprusiato Fe [Fe (CN)₅NO] ·5H₂O. Superf. vacío [online]. 2009, vol.22, n.4, pp.20-23. ISSN 1665-3521.

Metal transition nitroprussides have been the subject of diverse investigations in the last 30 years because of its interesting optical, electrical and magnetic properties induced by complex changes in the electronic configuration of [Fe(CN)5NO]-² ion. In this work, the dielectric response of polycrystalline Fe[Fe(CN)₅NO]·5H₂O was investigated by impedance spectroscopy in the frequency range of 5Hz-13 MHz as a function of temperature, from 300 to 393 K. Polycrystalline samples were prepared by precipitation from FeCl₂ and Na₂[(CN)₅NO]·2H₂O aqueous solutions. Our results have shown a clear maximum in dielectric relaxation frequency as a function of the temperature at 370 K. Such a behavior has been observed during ferro-paraelectric transition in some other materials. An abrupt increase in the dielectric constant value at the same temperature suggest that Fe[Fe (CN)₅NO]-5H₂O has a ferroelectric type behavior around this temperature .

Palavras-chave : Ferroelectric; Impedance spectroscopy; Nitroprussides.