Strong Interfacial Coupling of Tunable Ni–NiO Nanocomposite Thin Films Formed by Self-Decomposition

Abstract

The next-generation spintronic devices including memristors, tunneling devices, or stochastic switching exert surging demands on magnetic nanostructures with novel coupling schemes. Taking advantage of a phase decomposition mechanism, a unique Ni−NiO nanocomposite has been demonstrated using a conventional pulsed laser deposition technique. Ni nanodomains are segregated from NiO and exhibit as faceted "emerald-cut" morphologies with tunable dimensions affected by the growth temperature. The sharp interfacial transition between ferromagnetic (002) Ni and antiferromagnetic (002) NiO, as characterized by highresolution transmission electron microscopy, introduces a strong exchange bias effect and magneto-optical coupling at room temperature. In situ heating−cooling X-ray diffraction (XRD) study confirms an irreversible phase transformation between Ni and NiO under ambient atmosphere. Synthesizing highly functional twophase nanocomposites with a simple bottom-up self-assembly via such a phase decomposition mechanism presents advantages in terms of epitaxial quality, surface coverage, interfacial coupling, and tunable nanomagnetism, which are valuable for new spintronic device implementation.

Tunable Magnetic and Optical Anisotropy in ZrO2‐Co Vertically Aligned Nanocomposites

“…[17,18,19,20,21] Several metals, such as gold (Au), nickel (Ni), iron (Fe), and copper (Cu), have been explored for their unique properties when coupled with nitrides or oxides in the VAN thin film form. [7,22,23,24] Co is a well-known ferromagnetic material with a large coercivity (H c ) and a high Curie temperature (T c = 1388 K), [25,26] and is a plasmonic metal. [27] Considering the unique ferromagnetic, plasmonic and coupled properties with great device potentials, [28,29,30,31] vertically aligned Co-based nanocomposites could be ideal for exploration.…”

Multiferroic Self-Assembled BaTiO3–Fe Vertically Aligned Nanocomposites on Mica Substrates toward Flexible Electronics

“…Multiferroic thin films have attracted great interests owing to the potential for applications in low-power logic-memory devices, radio- and high-frequency devices, high-sensitivity magnetic field sensors, and photocatalysis. − Several multiferroic single-phase oxides have been well explored, including BiFeO 3 , YMnO 3 , and Fe 3 O 4 . − Driven by the need to improve the magnetoelectric coupling behavior, artificial composite multiferroic systems with different microstructures have been studied, including particulate composites, laminated multilayer thin films, and vertically aligned nanocomposites (VANs). − A VAN is a composite containing two or more phases, where one phase grows as nanopillars within the other phase, which grows as the matrix. Such a structure presents the advantages of achieving out-of-plane anisotropy in the magnetic property, easy tuning multiferroic, and other properties by structural and strain tuning, as well as the potential toward integrating other functionalities such as optical and plasmonic properties. − Most of the multiferroic nanocomposites have been integrated on single-crystalline oxide substrates with limited success on other substrates such as Si(001). − …”

Design of Nanoarchitectures for Magnetoplasmonic Biosensing with Near-Zero-Transmittance Conditions

“…Attempts to overcome the latter limitation include the use of quantum plasmonics and magnetoplasmonics . In fact, magnetoplasmonic nanostructures with ferromagnetic materials possessing plasmonic and magneto-optical (MO) activity are leading to breakthroughs − in such areas as telecommunications, − filtering, , biosensing, − and information storage/processing. − In these applications, MO effects are enhanced by combining large localized electromagnetic fields with plasmonic resonances. , The transverse MO Kerr effect (TMOKE), for instance, may be applied in biosensing and magnetometry since it is highly sensitive to changes in the refractive index and magnetization near the sample surface. Using TMOKE also enables ultrafast magnetism through all-optical modulation with femtosecond laser pulses. , In TMOKE, one measures the relative change in the transmitted or reflected light intensity for p -polarized waves obliquely impinging on a magnetic surface when the magnetization is reversed.…”