Spectroscopic characterization of mixed cation diphosphates of the type MIFeIIIP2O7 (with MI=Li, Na, K, Rb, Cs, Ag)

• Published in: The Journal of physics and chemistry of solids Vol. 74; no. 2; pp. 354 - 359
• Main Authors: Parajón-Costa, B.S., Mercader, R.C., Baran, E.J.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.02.2013
• Subjects: A. Inorganic compounds; B. Chemical synthesis; C. Infrared spectroscopy; C. Mössbauer spectroscopy; C. Raman spectroscopy; Cations; Coprecipitation; Diffraction; Diphosphates; Distortion; Infrared; Nitrates; Spectra; X-rays; B. Chemical synthesis; C. Raman spectroscopy; A. Inorganic compounds; C. Mössbauer spectroscopy; C. Infrared spectroscopy
• ISSN: 0022-3697; 1879-2553
• DOI: 10.1016/j.jpcs.2012.10.012

The mixed cation diphosphates of composition MIFeIIIP2O7 have been prepared using the so called co-precipitation method starting with Fe(III) and M(I) nitrate solutions and solid (NH4)H2PO4, and characterized by X-ray powder diffractometry. The infrared and Raman spectra of the compounds were recorded and the results are briefly discussed on the basis of their structural peculiarities. The 57Fe-Mössbauer spectra show that the typical high-spin FeIIIO6 octahedra existent in these compounds exhibit almost no distortion. However, the hyperfine parameters are sensitive to some characteristics of the MI cations and to the different structural types. ► Diphosphates of composition MIFeIIIP2O7 were prepared by the co-precipitation method. ► IR and Raman spectra could be interpreted on the basis of the known structures. ► Small structural differences between these compounds were spectroscopically detected. ► 57Fe-Mössbauer spectra show that the FeIIIO6 octahedra are only weakly distorted.