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High critical current (Ic) in high magnetic fields (B) with minimal variations with respect to the orientation of the B field is demanded by many applications such as high-field magnets for fusion systems. Motivated by this, this work studies 6 vol. % BaZrO3/YBa2Cu3O7 (BZO/YBCO) multilayer nanocomposite films by stacking two 10 nm thick Ca0.3Y0.7Ba2Cu3O7 (CaY-123) spacers with three BZO/YBCO layers of thickness varied from 50 to 330 nm to make the total film thickness of 150–1000 nm. The Ca diffusion from the spacers into BZO/YBCO was shown to dramatically enhance pinning efficiency of c-axis aligned BZO nanorods, which yields high and almost thickness independent critical current density (Jc) in the BZO/YBCO multilayer nanocomposite films. Remarkably, enhanced Jc was observed in these multilayer samples at a wide temperature range of 20–80 K and magnetic fields up to 9.0 T. In particular, the thicker BZO/YBCO multilayer films outperform their thinner counterparts in both higher value and less anisotropy of Jc at lower temperatures and higher fields. At 20 K and 9.0 T, Ic is up to 654 A/cm-width at B//c in the 6% multilayer (1000 nm) sample, which is close to 753 A/cm-width at B//ab due to the intrinsic pinning. This result illustrates the critical role of the Ca cation diffusion into the YBCO lattice in achieving high and isotropic pinning in thick BZO/YBCO multilayer films. 

Contact engineering on monolayer layer (ML) semiconducting transition metal dichalcogenides (TMDs) is considered the most challenging problem towards using these materials as a transistor channel in future advanced technology nodes. The typically observed strong Femi level pinning induced in part by the reaction of the source/drain contact metal and the ML TMD frequently results in a large Schottky barrier height, which limits the electrical performance of ML TMD field-effect transistors (FETs). However, at a microscopic level, little is known about how interface defects or reaction sites impact the electrical performance of ML TMD FETs. In this work, we have performed statistically meaningful electrical measurements on at least 120 FETs combined with careful surface analysis to unveil contact resistance dependencies on the interface chemistry. In particular, we achieved a low contact resistance for ML MoS2 FETs with ultra-high vacuum (UHV, 3×10-11 mbar) deposited Ni contacts, ~500 ohm·μm, which is 5 times lower than the contact resistance achieved when deposited at high vacuum (HV, 3×10-6 mbar) conditions. These electrical results strongly correlate with our surface analysis observations. X-ray photoelectron spectroscopy (XPS) revealed significant bonding species between Ni and MoS2 under UHV conditions compared to HV. We also studied the Bi/MoS2 interface under UHV and HV deposition conditions. Different from the case of Ni, we do not observe a difference in contact resistance or interface chemistry between contacts deposited under UHV and HV. Finally, this article also explores the thermal stability and reliability of the two contact metals employed here. 

Magnetic and ferroelectric oxide thin films have long been studied for their applications in electronics, optics, and sensors. The properties of these oxide thin films are highly dependent on the film growth quality and conditions. To maximize the film quality, epitaxial oxide thin films are frequently grown on single‐crystal oxide substrates such as strontium titanate (SrTiO₃) and lanthanum aluminate (LaAlO₃) to satisfy lattice matching and minimize defect formation. However, these single‐crystal oxide substrates cannot readily be used in practical applications due to their high cost, limited availability, and small wafer sizes. One leading solution to this challenge is film transfer. In this demonstration, a material from a new class of multiferroic oxides is selected, namely bismuth‐based layered oxides, for the transfer. A water‐soluble sacrificial layer of Sr₃Al₂O₆is inserted between the oxide substrate and the film, enabling the release of the film from the original substrate onto a polymer support layer. The films are transferred onto new substrates of silicon and lithium niobate (LiNbO₃) and the polymer layer is removed. These substrates allow for the future design of electronic and optical devices as well as sensors using this new group of multiferroic layered oxide films. 

Oxide-metal-based hybrid materials have gained great research interest in recent years owing to their potential for multifunctionality, property coupling, and tunability. Specifically, oxide-metal hybrid materials in a vertically aligned nanocomposite (VAN) form could produce pronounced anisotropic physical properties, e.g. , hyperbolic optical properties. Herein, self-assembled HfO 2 -Au nanocomposites with ultra-fine vertically aligned Au nanopillars (as fine as 3 nm in diameter) embedded in a HfO 2 matrix were fabricated using a one-step self-assembly process. The film crystallinity and pillar uniformity can be obviously improved by adding an ultra-thin TiN-Au buffer layer during the growth. The HfO 2 -Au hybrid VAN films show an obvious plasmonic resonance at 480 nm, which is much lower than the typical plasmonic resonance wavelength of Au nanostructures, and is attributed to the well-aligned ultra-fine Au nanopillars. Coupled with the broad hyperbolic dispersion ranging from 1050 nm to 1800 nm in wavelength, and unique dielectric HfO 2 , this nanoscale hybrid plasmonic metamaterial presents strong potential for the design of future integrated optical and electronic switching devices. 

Multiferroic materials are an interesting functional material family combining two ferroic orderings, e.g. , ferroelectric and ferromagnetic orderings, or ferroelectric and antiferromagnetic orderings, and find various device applications, such as spintronics, multiferroic tunnel junctions, etc. Coupling multiferroic materials with plasmonic nanostructures offers great potential for optical-based switching in these devices. Here, we report a novel nanocomposite system consisting of layered Bi 1.25 AlMnO 3.25 (BAMO) as a multiferroic matrix and well dispersed plasmonic Au nanoparticles (NPs) and demonstrate that the Au nanoparticle morphology and the nanocomposite properties can be effectively tuned. Specifically, the Au particle size can be tuned from 6.82 nm to 31.59 nm and the 6.82 nm one presents the optimum ferroelectric and ferromagnetic properties and plasmonic properties. Besides the room temperature multiferroic properties, the BAMO-Au nanocomposite system presents other unique functionalities including localized surface plasmon resonance (LSPR), hyperbolicity in the visible region, and magneto-optical coupling, which can all be effectively tailored through morphology tuning. This study demonstrates the feasibility of coupling single phase multiferroic oxides with plasmonic metals for complex nanocomposite designs towards optically switchable spintronics and other memory devices.