Large Magnetization and Frustration Switching of Magnetoresistance in the Double‐Perovskite Ferrimagnet Mn2FeReO6 |
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Authors: | Dr Angel M Arévalo‐López Graham M McNally Prof J Paul Attfield |
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Institution: | Centre for Science at Extreme Conditions (CSEC) and School of Chemistry, University of Edinburgh, Mayfield Road, Edinburgh EH9 3JZ (UK) |
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Abstract: | Ferrimagnetic A2BB′O6 double perovskites, such as Sr2FeMoO6, 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, Mn2FeReO6, synthesized at high pressure which has a high Curie temperature of 520 K and magnetizations of up to 5.0 μB 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 Mn2+ spin ordering which cants Fe3+ and Re5+ spins and reduces spin‐polarization. Ferrimagnetic double perovskites based on A‐site Mn2+ thus offer new opportunities to enhance magnetization and control magnetoresistance in spintronic materials. |
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Keywords: | ferrimagnetic double perovskites high‐pressure chemistry magnetic properties magnetoresistance perovskite phases |
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