ausblenden:
Schlagwörter:
-
Zusammenfassung:
We suceeded in the preparation of polycrystalline Ca2FeReO6 which has a
Curie temperature T-C of 540 K, the highest value of all magnetic
perovskites investigated till now. This material has been characterised
by X-ray and neutron powder diffraction. We found at 548 K, a monoclinic
unit cell (space group P2(1)/n) with a = 5.4366(5) Angstrom, b =
5.5393(5) Angstrom, c = 7.7344(5) Angstrom, and beta = 90.044(4)degrees.
For temperatures below 400 K, a phase separation in two monoclinic
phases with identical cell volume is observed in neutron scattering. The
two phases possess different magnetic structure and coercivity. The
conductivity is thermally activated for all temperatures and no
significant magnetoresistivity is observed. (C) 2002 Elsevier Science
Ltd. All rights reserved.
