Mechanical Modulation of Colossal Magnetoresistance in Flexible Epitaxial Perovskite Manganite

Abstract

Heteroepitaxially flexible oxide systems have been intensely developed and considered as the most promising materials for leading the creation of next-generation flexible electronic devices. Among them, perovskite manganites have attracted significant attention with their abundant and novel properties such as colossal magnetoresistance (CMR) and metal-insulator transition. However, the requirement of high quality samples hampers this field, not to mention the advanced nanoengineering. In this study, fluorophlogopite mica (F-mica) is selected as a flexible substrate to fabricate heteroepitaxial Pr 0.5 Ca 0.5 MnO 3 (PCMO) with a nanocolumn structure. Through a precise control of thickness, different morphologies are realized to manipulate the magnetotransport properties (reduction of melting field). Moreover, thanks to the excellent flexibility of F-mica, mechanical modulation of CMR (≈1000%) can be achieved in different flex modes while the magnetic properties remain unaffected. Detailed bending tests are performed to study the behavior of resistive change (≈30%). Through the combination of high flexibility, high quality PCMO, and well-designed nanocolumn structure, the study exhibits the significant controllability of CMR via mechanical bending, and manifests the potential of such a heteroepitaxially flexible oxide system which can be applied on flexible magnetoresistive devices and sensors.

Wafer-Scale Epitaxy of Flexible Nitride Films with Superior Plasmonic and Superconducting Performance

“…F-mica was carefully selected for the following reasons. First, F-mica is chemically inert, thermally stable up to ∼1100 °C, and atomically flat on the surface. , These properties are highly favorable for refractory plasmonic applications and patterning devices on F-mica. Second, F-mica is highly insulating with low dielectric loss in the high-frequency range, which is essential for superconducting quantum resonators and qubits with long coherence times .…”

“…Second, F-mica is highly insulating with low dielectric loss in the high-frequency range, which is essential for superconducting quantum resonators and qubits with long coherence times . Lastly, F-mica is mechanically robust, which can be exfoliated to thicknesses of micrometers and repeatedly bent. − , Generally, the muscovite mica can be stable below the growth temperature of 700 °C . The thermally more stable F-mica was used to synthesize highly crystalline topological insulator, metal, and functional oxide ,, films via different deposition techniques (Table S1 in the Supporting Information).…”

“…Lastly, F-mica is mechanically robust, which can be exfoliated to thicknesses of micrometers and repeatedly bent. − , Generally, the muscovite mica can be stable below the growth temperature of 700 °C . The thermally more stable F-mica was used to synthesize highly crystalline topological insulator, metal, and functional oxide ,, films via different deposition techniques (Table S1 in the Supporting Information). For example, single-crystalline Bi 2 Se 3 films have been successfully grown on F-mica substrates using a vapor-phase deposition .…”

“…Ideally, single-crystalline films are more preferred over other less-crystalline films due to their superior physical performance (e.g., piezoelectric coefficient, carrier mobility, ferromagnetic resonance width). − However, the epitaxial growth of films on the flexible substrates is still very challenging for many functional materials, especially at the wafer scale, a prerequisite for massive device fabrications. So far, only small groups of flexible single-crystalline films, including two-dimensional materials (e.g., graphene, MoS 2 , h-BN), − a few transition-metal-oxide (TMO) films, − etc., have been reported.…”

Eu–Mn Charge Transfer and the Strong Charge–Spin–Electronic Coupling Behavior in EuMnO3

“…Rare-earth (RE) manganites have attracted wide attention in the field of spintronics due to a variety of stunning physical phenomena such as colossal magnetoresistance and magnetic multiferroics, which arise from the couplings of lattice, charge, spin, and orbital degrees of freedom under the frame of strongly correlated systems. − These subtle competing interactions could be finely tuned by external parameters such as chemical pressure, hydrostatic pressure, and strain, which leads to fruitful functional properties for practical applications and wins the favor of fundamental research. − Especially, RE elements with a quasicontinuous ionic size and 4f n configurations may contribute to the modulation of local geometric, electronic, and magnetic microstructures simultaneously. , However, the interaction between RE-4f states and Mn-3d states has not attracted enough attention and the role of 4f electrons is still an open issue.…”