VIII VI IV Aenigmatite, Na4 (Fe2 +,Ti,Fe 3 +) 1 2 (SiFe 3 +) 12 0 40 , is a common constituent of sodium-rich alkaline igneous rocks and is classified as an open-branched single-chain silicate, whose structure is closely related to that of sapphirine. The first Mossbauer spectra of three valid aenigmatite specimens were recorded and the detailed crystal chemistry were obtained. In the Mossbauer...

Slow (zero field)paramagnetic relaxation is reported for undiluted tetrahedral ferrous monomers for the first time. The Mossbauer spectra of Fe(2,9 di-CH3-phenanthroline)(NCS)2 and Fe(2,9 di-CH3 4,7 di-(j>-phenanthroline) (NCS)2 exhibit magnetic hyperfine splitting in the range 20 K to 1.6 K while the corresponding chlorides are rapidly relaxing paramagnets at all temperatures in zero field. Lo...

The Mossbauer spectra of Fe in Fe3 _ xVx Si alloys for 0.,;; x";; I shows that V occupies almost exclusively one of two Fe sites (the B site). As x increases the spectra of Fe on the other site (the A, C site) becomes increasingly complex as the number of their V 1st neighbors increases. Simulated Mossbauer spectra were calculated using moments obtained by a simple model from bulk magnetization...

Mossbauer studies of the ubiquitous protein molecule ferritin and its synthetic "biomimic" polysaccharide iron complex (pIC) exhibit an anomaly in the Mossbauer spectrum wherein the recoil free fraction orf-factor has a sharp drop with respect to temperature as the temperature rises above 30 K for mammalian ferritin and 60 K for PIC. The anomaly coincides with the disappearance ofhyperfme split...

Confirmation of the suggestion of B site zn2+ in nanocrystalline ZnFe204 has heen sought through X-ray diffraction, 5 7 ~ e Miissbauer spectroscopy, magnetic susceptibility and TEM measurements on bulk and nanocrystalline samples prepared by different techniques. Measurements on bulk samples are in agreement with previously reported ones. Samples prepared at low temperature from solutions of sa...

In this work we have studied several NdFeB compositionally modulated thin films by using both conversion electron Mossbauer spectra and SOUIP magnetometry. Both the hyperfine fields and the easy magnetization magnitude are not correlated with the modulation characteristic length ( A ) while the magnetization perpendicular to the thin film plane decreases as A increases.

The MnNb(2)O(6)-FeNb(2)O(6) solid solution has been investigated by Fe-K- and Mn-K-edge X-ray absorption (XANES and EXAFS), and Mossbauer spectroscopy. The first-shell M-O bond lengths deduced from EXAFS show a fairly small compositional dependence. A degree of static disorder, which increases with increasing manganese content, is clearly seen by the loss of correlation for the next-neighbour (...

We have analysed in terms of static hyperfine field distributions the Mossbauer spectra of mixed Zn-Mg ferrites. Typical features of semi-spin glasses are observed both in average and locally: in each sample, the relevant data are smeared out in a way which reveals the behavior of the series.

Mossbauer spectra of MnFez04 with various particle sizes in a longitudinal 50 kOe magnetic field show that the Fe ion occupancy of the A and B crystallographic sites depends on the particle size. The elevated N6el temperatures with decreasing particle sizes are attributed to an increased iron occupancy on the A sites; this in turn leads to an increase in the total superexchange interaction.