Potassium hexacyanoferrate(II) trihydrate, K4Fe(CN) 6 9 3HeO, was heated under controlled conditions of mass and rate in a derivatograph in the presence of oxygen. The heating was stopped at different temperatures and Mbssbauer spectra and X-ray diffractograms were taken on the quenched material at room temperature. The reaction pathway was studied in this way and the advantages and drawbacks of each of the techniques are described. At different stages of the thermal process we were able to show the presence of K4Fe(CN)~, c~-Fe203, F%O~, FeaC, Fe, FeO, KFeO2,/3-FeOOH, KOCN, K~CO 3 and KCN.

No abstract

A natural sample of Almandine, Fe3Al2 (SiO4)3, was studied by 57Fe Mössbauer Spectroscopy at various temperatures. The values for the Electric Field Gradient tensor components have been determined from the lowest temperature (2K) spectrum to be: Vzz = −1.75 × 10−18 V/cm2, Vxx = 0.82 × 10−18 V/cm2 and Vyy = 0.92 × 10−18 V/cm2. The separation between the two electronic lower levels is inferred from a simple model for the quadrupolar interaction. The lower level is a dz2-one and is 872 cm−1 (similar 1250K) below the first excited state which is a dxy-state. Both constitute the 5Eg-doublet.

No abstract

No abstract