In this paper, we report on a purely electric mechanism for achieving the electric control of the interfacial spin polarization and magnetoresistance in multiferroic tunneling junctions. We investigate micrometric devices based on the Co/Fe/BaTiO3/La0.7Sr0.3MnO3 heterostructure, where Co/Fe and La0.7Sr0.3MnO3 are the magnetic electrodes and BaTiO3 acts both as a ferroelectric element and tunneling barrier. We show that, at 20 K, devices with a 2 nm thick BaTiO3 barrier present both tunneling electroresistance (TER = 12   ±   0.1%) and tunneling magnetoresistance (TMR). The latter depends on the direction of the BaTiO3 polarization, displaying a sizable change of the TMR from  -0.32   ±   0.05% for the polarization pointing towards Fe, to  -0.12   ±   0.05% for the opposite direction. This is consistent with the on-off switching of the Fe magnetization at the Fe/BaTiO3 interface, driven by the BaTiO3 polarization, we have previously demonstrated in x-ray magnetic circular dichroism experiments.

Electric field control of magnetic properties and electron transport in BaTiO3-based multiferroic heterostructures

ASA, MARCO;BALDRATI, LORENZO;RINALDI, CHRISTIAN;BERTOLI, STEFANO;RADAELLI, GRETA;CANTONI, MATTEO;BERTACCO, RICCARDO
2015

Abstract

In this paper, we report on a purely electric mechanism for achieving the electric control of the interfacial spin polarization and magnetoresistance in multiferroic tunneling junctions. We investigate micrometric devices based on the Co/Fe/BaTiO3/La0.7Sr0.3MnO3 heterostructure, where Co/Fe and La0.7Sr0.3MnO3 are the magnetic electrodes and BaTiO3 acts both as a ferroelectric element and tunneling barrier. We show that, at 20 K, devices with a 2 nm thick BaTiO3 barrier present both tunneling electroresistance (TER = 12   ±   0.1%) and tunneling magnetoresistance (TMR). The latter depends on the direction of the BaTiO3 polarization, displaying a sizable change of the TMR from  -0.32   ±   0.05% for the polarization pointing towards Fe, to  -0.12   ±   0.05% for the opposite direction. This is consistent with the on-off switching of the Fe magnetization at the Fe/BaTiO3 interface, driven by the BaTiO3 polarization, we have previously demonstrated in x-ray magnetic circular dichroism experiments.
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11311/970807
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