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Large Magnetization and Frustration Switching of Magnetoresistance in the Double‐Perovskite Ferrimagnet Mn 2 FeReO 6
Author(s) -
ArévaloLópez Angel M.,
McNally Graham M.,
Attfield J. Paul
Publication year - 2015
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201506540
Subject(s) - ferrimagnetism , magnetoresistance , condensed matter physics , magnetization , antiferromagnetism , spintronics , frustration , curie temperature , neutron diffraction , materials science , perovskite (structure) , colossal magnetoresistance , ferromagnetism , chemistry , magnetic field , crystallography , physics , crystal structure , quantum mechanics
Ferrimagnetic A 2 BB′O 6 double perovskites, such as Sr 2 FeMoO 6 , are important spin‐polarized conductors. Introducing transition metals at the A‐sites offers new possibilities to increase magnetization and tune magnetoresistance. Herein we report a ferrimagnetic double perovskite, Mn 2 FeReO 6 , synthesized at high pressure which has a high Curie temperature of 520 K and magnetizations of up to 5.0 μ B which greatly exceed those for other double perovskite ferrimagnets. A novel switching transition is discovered at 75 K where magnetoresistance changes from conventional negative tunneling behavior to large positive values, up to 265 % at 7 T and 20 K. Neutron diffraction shows that the switch is driven by magnetic frustration from antiferromagnetic Mn 2+ spin ordering which cants Fe 3+ and Re 5+ spins and reduces spin‐polarization. Ferrimagnetic double perovskites based on A‐site Mn 2+ thus offer new opportunities to enhance magnetization and control magnetoresistance in spintronic materials.