BLOCKS WITHIN CRYSTAL-STRUCTURE AND BEHAV IOR PECULARITIES OF MN2+ AND FE2+ IN CORDIERITE

Chemical, structural, and ESR-data are reported for ten natural cordie rite samples. The difference in the principal features of Fe2+ and Mn2 + distributions between various structural constituents of crystals (b locks and zones of interblock boundaries) have been established by mea ns of ESR and microprobe chemical analysis. The variations of line wid th in ESR-spectra of Mn2+-ions mainly depend on the iron concentration in the samples, Fe2+-effect: Delta H(Mn2+)Gs = 9 . 10(-21) x n (Fe2+) (spin/cm(3)) corresponds to the interaction of magnetic dipoles. Anis otropy of line width of Mn2+-ions is mainly accounted for by the Fe2and Be2+ influence in accordance with the electrostatic mechanism. Con centration of Mn2+-ions in the perfect part of the examined crystals i s practically constant (0.0n wt.% MnO) and ranges from 5 to 65% of tot al MnO content in cordierites of various genetic types.