Magnetic-field-induced avalanches in magnetization and magnetoresistance of La0.9Ce0.1Fe12B6 compound
Résumé
Competition between paramagnetic (PM), antiferromagnetic (AFM) and ferromagnetic (FM) phases in La0.9Ce0.1Fe12B6 itinerant-electron metamagnetic system is studied by a combination of magnetic, electrical resistivity and magnetoresistance measurements. La0.9Ce0.1Fe12B6 is an antiferromagnet below the Néel temperature (35 K) and presents two consecutive magnetic transitions AFM-FM and FM-PM during warming under certain applied magnetic field values. We further demonstrate that both AFM and PM phases may be converted into the FM phase irreversibly and reversibly via a first-order metamagnetic transition accompanied by a large magnetic field hysteresis. At very low temperatures, the magnetic-field driven AFM-FM metamagnetic transformation is discontinuous and proceeds by multiple abrupt steps in magnetization and magnetoresistance. In addition, an extraordinarily large negative magnetoresistance (MR) effect of -77% is observed. The consistency found in the magnetotransport and magnetization data suggests strong correlations between charge and spin degrees of freedom in La0.9Ce0.1Fe12B6 system.
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