Tunneling magnetoresistance with positive and negative sign in La0.67Sr0.33MnO3/SrTiO3/Co junctions
نویسندگان
چکیده
We have investigated the effects of modification of the SrTiO3/Co interface as well as the SrTiO3 barrier on the tunnel magnetoresistance TMR of La0.67Sr0.33MnO3/SrTiO3/Co junctions. Modification was realized by the introduction of one atomic layer of either TiO2 or SrO at the SrTiO3/Co interface. Barriers with different oxygen content were also studied. In these structures we have observed positive as well as negative TMR, with a trend towards positive TMR for junctions with interfacial SrO and/or more oxygen-deficient barriers. This work offers more insight into the SrTiO3/Co tunnel spin polarization and its sign.
منابع مشابه
J ul 1 99 8 Thin - Film Trilayer Manganate Junctions
Spin-dependent conductance across a manganate-barrier-manganate junction has recently been demonstrated. The junction is a La0.67Sr0.33MnO3-SrTiO3-La0.67 Sr0.33MnO3 trilayer device supporting current-perpendicular transport. Large magnetoresistance of up to a factor of five change was observed in these junctions at 4.2K in a relatively low field of the order of 100 Oe. Temperature and bias depe...
متن کاملResonant inversion of tunneling magnetoresistance.
Resonant tunneling via localized states in the barrier can invert magnetoresistance in magnetic tunnel junctions. Experiments performed on electrodeposited Ni/NiO/Co nanojunctions of area smaller than 0.01 microm(2) show that both positive and negative values of magnetoresistance are possible. Calculations based on Landauer-Büttiker theory explain this behavior in terms of disorder-driven stati...
متن کاملPolarity-tunable magnetic tunnel junctions based on ferromagnetism at oxide heterointerfaces
Complex oxide systems have attracted considerable attention because of their fascinating properties, including the magnetic ordering at the conducting interface between two band insulators, such as LaAlO3 and SrTiO3. However, the manipulation of the spin degree of freedom at the LaAlO3/SrTiO3 heterointerface has remained elusive. Here, we have fabricated hybrid magnetic tunnel junctions consist...
متن کاملAtomic, electronic, and magnetic properties of magnetic tunnel junctions
We report results of first-principles density-functional studies of the atomic and electronic structure of Co/Al2O3 /Co and Co/SrTiO3 /Co magnetic tunnel junctions ~MTJs!. The atomic structure has been studied for different interface terminations and the interfacial energetics was quantified based on the work of separation. Based on energetics of cohesion, the O-terminated and TiO2-terminated i...
متن کاملMetal-Oxide Interfaces in Magnetic Tunnel Junctions
Metal-oxide interfaces play an important role in spintronics—a new area of microelectronics that exploits spin of electrons in addition to the traditional charge degree of freedom to enhance the performance of existing semiconductor devices. Magnetic tunnel junctions (MTJs) consisting of spin-polarized ferromagnetic electrodes sandwiching an insulating barrier are such promising candidates of s...
متن کامل