Observation of large low-field magnetoresistance in trilayer perpendicular transport devices made using doped manganate perovskites

Abstract

We report on the fabrication of a new class of trilayer epitaxial thin film devices based on the doped perovskite manganates La–Ca–Mn–O and La–Sr–Mn–O. We show that large resistance changes, up to a factor of 2, can be induced by a moderate applied magnetic field below 200 Oe in these trilayers supporting current-perpendicular-to-plane transport. These results show that low-field spin-dependent transport in manganates can be accomplished, the magnitude of which is suitable for magnetoresistive field sensors.

Nonequilibrium transport and optical properties of model metal–Mott-insulator–metal heterostructures

“…Detailed analysis of the transport properties of correlated heterostructures including current-voltage characteristics is directly relevant to device applications. 10,11,12,13 However, this area remains largely unexplored.…”

High-Temperature Magnetic Insulating Phase in UltrathinLa0.67Sr0.33MnO3Films

“…The perovskite manganite La 0.67 Sr 0.33 MnO 3 (LSMO) is widely used in spintronics, because of its half metallicity and high T C of 370 K [11][12][13][14]. This has resulted in magnetic tunnel junctions with exceptionally large tunnel magnetoresistance ratio [13].…”

Growth mode transition from layer by layer to step flow during the growth of heteroepitaxial SrRuO3 on (001) SrTiO3

“…[1][2][3] In such a tunnel junction, the junction magnetoresistance ͑JMR͒ is determined by the difference in the density of states for tunneling. Highly spin-polarized magnetic oxides, halfmetallic oxides, are expected to exhibit large, almost infinite JMR in the Julliere model.…”

“…4 In reality, it has been shown that there is a strong temperature dependence of the JMR in the doped manganite system, i.e., premature loss below the Curie temperature. 1 This result is important for technological applications and depends on the quality of the junctions: uniformity and quality of barrier layer, interface sharpness, and surface magnetization. For the study of its physical origin, the sharp interface and defect-free barrier layer in the trilayered tunnel junction are required and must be controlled on an atomic scale.…”