Asymmetric interfaces and high-TC ferromagnetic phase in La0.67Ca0.33MnO3/SrRuO3 superlattices

Abstract

Interfacial magnetism in functional oxide heterostructures not only exhibits intriguing physical phenomena but also implies great potential for device applications. In these systems, interfacial structural and electronic reconstructions are essential for improving the stability and tunability of the magnetic properties. In this work, we constructed ultra-thin La 0.67 Ca 0.33 MnO 3 (LCMO) and SrRuO 3 (SRO) layers into superlattices, which exhibited a robust ferromagnetic phase. The high Curie temperature (T C ) reaches 291 K, more than 30 K higher than that of bulk LCMO. We found that the LCMO/SRO superlattices consisted of atomically-sharp and asymmetric heterointerfaces. Such a unique interface structure can trigger a sizable charge transfer as well as a ferroelectric-like polar distortion. These two interfacial effects cooperatively stabilized the high-T C ferromagnetic phase. Our results could pave a promising approach towards effective control of interfacial magnetism and new designs of oxide-based spintronic devices.

Extreme Enhanced Curie Temperature and Perpendicular Exchange Bias in Freestanding Ferromagnetic Superlattices

“…The exchange integral is proportional to the bond angle of Mn 3+ –O–Mn 4+ . Therefore, the decrease of the modulation thickness can enhance the interfacial tensile strain and bond angle of Mn 3+ –O–Mn 4+ , which is beneficial to strengthen the ferromagnetic double-exchange interaction and T c . ,, In addition, the cationic interdiffusion at the LCMO/SRO interface could occur, which usually can not be avoided in the epitaxy by pulsed laser deposition at high temperatures and can result in the transformation of magnetic properties. For the SRO layer, the decreased temperature of the magnetic ordering is expected via the La, Ca, or Mn doping according to the previous literature. − In the LCMO, the Sr diffusion from SRO can contribute to higher T c , benefiting from the optimized tolerance factor between two neighboring Mn, which was consistent with our observation of enhanced T c at the LCMO/SRO interface.…”

“…Therefore, the decrease of the modulation thickness can enhance the interfacial tensile strain and bond angle of Mn 3+ −O−Mn 4+ , which is beneficial to strengthen the ferromagnetic double-exchange interaction and T c . 21,40,41 In addition, the cationic interdiffusion at the LCMO/SRO interface could occur, which usually can not be avoided in the epitaxy by pulsed laser deposition at high temperatures and can result in the transformation of magnetic properties. For the SRO layer, the decreased temperature of the magnetic ordering is expected via the La, Ca, or Mn doping according to the previous literature.…”

Correlated Quantum Phenomena of Spin–Orbit Coupled Perovskite Oxide Heterostructures: Cases of SrRuO3 and SrIrO3 Based Artificial Superlattices

“…Table 2 summarizes the reported SrRuO 3 based superlattices with various functional partner compounds. [ 41,54,55,70,86–164 ] Herein, several emergent functionalities of SrRuO 3 based superlattices and their modulations are reviewed in the following Sections.…”

Tuning of Interlayer Interaction in MoS2–WS2 van der Waals Heterostructures Using Hydrostatic Pressure

“…Specifically, the twist angle and lattice shift between HS layers provide an effective method to alter interlayer interactions, which can be done by varying the interlayer distance . For this reason, this method can be used to modulate and affect electronic properties of materials, leading to the induction of new quantum phenomena, including superconductivity, magnetism, and insulating states. ,− Practically, the application of hydrostatic pressure by a diamond anvil cell (DAC) has been proven to be another tool to control interlayer interactions and thus achieve electronic transitions in 2D TMDs and HSs. ,− Indeed, hydrostatic pressure can considerably reduce distances between atoms and modify the nature of their interactions. Furthermore, interlayer interactions are much weaker than intralayer covalent bonds, which makes it possible to modulate them much more efficiently than intralayer interactions by compression.…”