Enhanced spin injection and detection in spin valves with integrated tunnel barriers

Abstract

We study the spin-dependent transport in lateral spin-valve devices with aluminum oxide tunnel barriers at the interfaces between NiFe electrodes and an interconnecting Al strip. Different total conductivities per cross-sectional area are achieved by varying the oxygen pressure, the oxidation time, and the thickness of the oxidized aluminum layer. The experimental data are consistent with our theoretical description including spin diffusion, spin relaxation, and tunnel barriers at the interfaces between electrodes and aluminum strip. With decreasing tunnel conductance the amplitude of the nonlocal spin-valve effect increases by two orders of magnitude up to saturation.

Efficient spin injection into nonmagnetic metals through low-resistance MgO

“…For the NLSV signal, DR S shows a similar value for the Co/Al 2 O 3 /Al tunnel junction, 8 but the value is higher than that of Py/Al 2 O 3 /Al and Py/Al 2 O 3 /Cu tunnel junctions in a similar lateral geometry. 15,16 Figure 3 shows the R I dependence of DR S for the LSV [Fig. 3(a)] and NLSV [ Fig.…”

All-metal lateral spin valve operated by spin pumping

“…For spin injection in a conventional nonlocal lateral spin valve, 5,[8][9][10] a charge current is driven from a ferromagnet (injector electrode, F I ) into a nonmagnetic normal metal (N ). For nomenclature see Fig.…”

“…The measurement signal depends on the relative orientation of the magnetizations of the electrodes. 5,[8][9][10] When the configuration switches from parallel to antiparallel, the voltage changes its sign. The change of sign of the detected voltage should not depend on the mechanism creating the spin current.…”

“…All-metal lateral spin valves are workhorses in the field of spin electronics and play an important role in spin transport. [1][2][3][4][5][6][7][8][9][10][11] In spin valves, spin currents can be generated, manipulated, and detected. Conventionally a spin current is created by sending a charge current through the interface between a ferromagnet and a normal metal.…”

Large and inverted spin signals in nonlocal spin valves

“…The oxide layer at F/N interface has been shown to increase the values of P 1 and P 2 for NLSV structures. 7,[17][18][19] The width of the Cu channel is 100 -120 nm and widths of F 1 and F 2 electrodes are typically 60 -80 nm. The center-to-center distance between F 1 and F 2 varies between 200 and 500 nm.…”