Transport across conducting ferromagnetic oxide/metal interfaces

Abstract

We have investigated transport properties across interfaces between the conducting ferromagnetic oxides SrRuO3, La0.5Sr0.5CoO3, La0.67Sr0.33MnO3, and the metals Nb, Al, Pd, and Au. The interface resistances range from smaller than 10−8 to 102 Ω cm2, depending on the choice of ferromagnetic oxide and metal. The three conducting metal oxides exhibit distinctly different behavior in their interface resistances with metals, which we believe is due to different processes taking place at the interface. By making the metals superconducting at 4.2 K, by proximity effect with a capping Nb layer, we show that the dominant transport mechanism through the resistive interface seems to be elastic tunneling. In the case of La0.67Sr0.33MnO3/Al interfaces, we found a way to control the magnitude of the tunneling resistance by adding a very thin Pd layer.

Magnetic proximity effect and superconducting triplet correlations at the cuprate superconductor and oxide spin valve interface

“…Using the data from Ref. 63 we find that the resistance of the SRO/Au interface can be estimated to be 0.05 lX cm 2 , whereas the resistance of the YBCO/SRO border is about 0.1 lX cm 2 , which is consistent with the data in Ref. 64.…”

“…If we assume that the resistance of the LSMO/Au border does not exceed the value of 1 lX cm 2 (Ref. 63) then the resistance of the YBCO/LSMO/Au mesastructure (100 lX cm 2 ) can be explained by the greater resistance of the YBCO/LSMO interface. Using the data from Ref.…”

Grain-boundary magnetoresistance in manganites: Spin-polarized inelastic tunneling through a spin-glass-like barrier

“…Mieville et al showed that some metal-manganite contacts have tunneling characteristics. 9 Since the transport mechanism in these contacts is supposed to be similar to the transport through grain boundaries, a Cr-LCMO contact ͑S5͒ was studied here.…”

Spin Transport in Carbon Nanotubes and Graphene: Experiments and Theory

“…3, we show the much larger MR ratios, ranging between 53 % and 72 %, found by Hueso et al [13] on a series of devices composed of a single MWNT connected to La 0.7 Sr 0.3 MnO 3 (LSMO) electrodes. The very large resistance of the devices, in the 10 MΩ range, comes predominantly from the existence of tunnel barriers between the CNT and the LSMO electrodes (as at most interfaces between LSMO and metals [14]), so that the resistance change between the P and AP configurations, also in the 10 MΩ range, cannot be due to some variation of the considerably smaller electrode or CNT resistances. It can be seen as the MR of a device composed of two tunnel junctions T 1 and T 2 with electrons propagating almost without spin flip between T 1 and T 2 .…”