Four-state non-volatile memory functions are demonstrated in all-oxide multiferroic tunnel junctions (MFTJs), composed of La0.7Sr0.3MnO3 and La0.7Sr0.3Mn0.8Ru0.2O3 ferromagnetic electrodes and a SrTiO3/BaTiO3 dielectric/ferroelectric composite barrier. Compared with MFTJs with a single BaTiO3 barrier, the insertion of a SrTiO3 dielectric barrier is shown effective to enhance both the electroresistance and the magnetoresistance of the MFTJs. In particular, the tunneling electroresistance ratio is greatly improved by two orders. This is discussed in terms of the enhanced asymmetry in the electrostatic modulation on the barrier profile with respect to the ferroelectric polarization direction.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)