Large Magnetoresistance in Magnetically Coupled SrRuO₃ –CoFe₂O₄ Self‐Assembled Nanostructures

Abstract

A new way to induce a large magnetoresistance has been achieved by self-assembled nanostructures consisting of ferromagnetic spinel CoFe₂O₄ (CFO) and metallic perovskite SrRuO₃ (SRO). The interdiffused Fe³⁺ ions in SRO have paved the way to strong magnetic couplings with CFO nanopillars, resulting in the suppression of spin-polarized electron scattering.

Evolution of microstructure, strain and physical properties in oxide nanocomposite films

“…Artificially constructed horizontal oxide heterointerfaces in the form of superlattices, multilayers, and/or heterostructures have been widely investigated to manipulate physical properties789. Recently, nanocomposites with a vertical interface network are emerging as an alternative approach to tune physical properties since microstructure, interfacial coupling, and lattice strain can be tailored from 2D to 3D10111213141516171819. The lack of substrate clamping effect and the presence of large interfacial area in thick vertically aligned nanocomposite films in comparison with conventional horizontal heterostructures make such a new 3D architecture attractive20 to tune the functionalities of materials21.…”

“…The structural, optical, and magnetic properties can be also tuned by film thickness363738. However most of the previous studies on heteroepitaxial oxide nanocomposite films focus on varying phase compositions3940, substrate orientations2441, material systems14424344, substrate lattice parameter and symmetry11294546, etc. The thickness effect, a key factor in composite films, is rarely studied.…”

Self‐assembled patterned CoFe2O4‐SrRuO3 electrodes: Enhanced functional properties by polar nano‐regions reorientation

“…For PMN‐PT compositions near the MPB, mixed phases are known, where structurally bridging monoclinic (M) states exist between T and R phases . Large piezoelectricity and dielectric properties result …”

“…A CoFe 2 O 4 ‐SrRuO 3 (CFO‐SRO) nanopillar heterostructure has recently been reported that consists of CFO nanopillars within a SRO matrix . In this heterostructure, the SRO serves as a conductive material and CFO as an insulating one.…”

Mesocrystal-embedded functional oxide systems

“…[30,31] To meet the criteria for practical applications, previous works have pointed out that the grain boundary in polycrystalline manganite can induce the spin tunneling and thus results in the enhanced MR in a relatively low magnetic field (H < 1 T). [32][33][34][35] Taking the advantage of mesocrystal-embedded system that possesses uniform artificial boundaries, Liu et al [36] observed an unexpectedly large MR in the magnetic mesocrystal-embedded SRO system. The correlation between the magnetic CFO mesocrystal and SRO matrix was investigated via the measurements of field-dependent transport [ Fig.…”