TY - JOUR
T1 - Heat-induced charge transfer in cobalt iron cyanide
AU - Martínez-García, R.
AU - Knobel, M.
AU - Goya, G.
AU - Gimenez, M. C.
AU - Romero, F. M.
AU - Reguera, E.
N1 - Funding Information:
R.M.G. thanks the support provided by CLAF-ICTP for his Ph.D. studies. Support from CNPq and FAPESP (Brazilian agencies) and the LNLS facilities are also acknowledged. The authors thank C. Vasquez-Ramos from IIM-UMAM (Mexico) the TGA data acquisition.
PY - 2006/11
Y1 - 2006/11
N2 - The heating of Co(2+) ferricyanide above 80 °C induces an inner charge transfer from Co(2+) towards Fe(III) to form the mixed valence system Co(2+)Co(III) ferri- ferro-cyanide. This charge transfer takes place preserving the material framework and forming a solid solution of the initial and final species. The cell edge of the cubic cell (Fm-3m) of this solid solution follows a regular variation with the material composition. This mixed valence system was characterized using X-ray diffraction, infrared, thermo-gravimetric, Mössbauer and magnetic measurements. Its formation is easily detected by the appearance of an intermediate ν(CN) absorption band in the infrared spectra at around 2120 cm-1, 40 cm-1 below and above the observed frequency for this vibration in Co(2+) ferri- and ferro-cyanide, respectively.
AB - The heating of Co(2+) ferricyanide above 80 °C induces an inner charge transfer from Co(2+) towards Fe(III) to form the mixed valence system Co(2+)Co(III) ferri- ferro-cyanide. This charge transfer takes place preserving the material framework and forming a solid solution of the initial and final species. The cell edge of the cubic cell (Fm-3m) of this solid solution follows a regular variation with the material composition. This mixed valence system was characterized using X-ray diffraction, infrared, thermo-gravimetric, Mössbauer and magnetic measurements. Its formation is easily detected by the appearance of an intermediate ν(CN) absorption band in the infrared spectra at around 2120 cm-1, 40 cm-1 below and above the observed frequency for this vibration in Co(2+) ferri- and ferro-cyanide, respectively.
KW - A. Inorganic compounds
KW - C. Infrared spectroscopy
KW - C. Mössbauer spectroscopy
KW - C. X-ray diffraction
KW - D. Crystal structure
UR - http://www.scopus.com/inward/record.url?scp=33749320287&partnerID=8YFLogxK
U2 - 10.1016/j.jpcs.2006.05.045
DO - 10.1016/j.jpcs.2006.05.045
M3 - Artículo
SN - 0022-3697
VL - 67
SP - 2289
EP - 2299
JO - Journal of Physics and Chemistry of Solids
JF - Journal of Physics and Chemistry of Solids
IS - 11
ER -