Untersuchung des M2/M3-Phasenübergangs in V1-xFexO2mit x = 0,024.

The Mössbauer investigations of V1-xFexO2with x = 0.024 indicate that Fe enters two cation positions of M2and M3. At the phase transition the two quadrupole splittings show a discontinuous behavior whereas the isomer shift changes continuously with a crossingover at the M2, M3transition (Tt′= 275 K). Generally a first order phase transition is accompanied by a change of the cell volume V and a change of the isomer shift. The observed continuous behavior of the isomer shift points to a first order transition with δV ≠ 0.