Search

The ferromagnetic properties are investigated in single crystal ZnO nanorods with heavy codoping of 28 at. % Mn and 1 at. % Fe fabricated by vapor phase transport. The electron energy loss spectroscopy and x-ray photoelectron spectroscopy confirmed that Mn and Fe dopants are, respectively, +2 and +3 valence states, where Raman scattering exhibited additional peaks at 308 cm−1, 458 cm−1, 480 cm−1, 504 cm−1, 516 cm−1, 530 cm−1, and 569 cm−1, associated with MnFe dopants. Compared with undoped and Mn doped ZnO nanostructures, the MnFe-codoped ZnO nanorods are strongly ferromagnetic below Tc of 39 K and around room temperature. The ferromagnetic behavior can be mainly attributed to the carrier-mediated Ruderman–Kittel–Kasuya–Yosida mechanism below Tc and the defect-induced bound magnetic polaron mechanism around room temperature. [ABSTRACT FROM AUTHOR]

The iodide interplay with polar Zn2+ and O2− induced nonpolar [10 1 ¯ 0] ZnO nanowires is fabricated via a simple vapor phase transport at a temperature of as low as 250 °C that is compatible with the nanodevice processing technique. As-fabricated nanowires exhibit single crystalline hexagonal wurtzite structures and grow along the [10 1 ¯ 0] direction instead of the conventional polar [0001] direction. The growth evolution can be explained by the synergy of the vapor–liquid–solid process and iodide direction-modulation. The electrical measurements demonstrate that the mobility of the PbI2-induced [10 1 ¯ 0] nanowires is significantly improved in comparison with that of the BiI3-modulated [11 2 ¯ 0] ones. These unique nonpolar nanowires are promising for improved high efficiency nanodevices. [ABSTRACT FROM AUTHOR]

Nickel silicides are widely used as contact materials for electronic devices based on silicon (Si). However, they have been predominantly fabricated by annealing separate Ni and Si phases which leads to phase and structural complexity. In this letter, direct epitaxial growth of a single-phase nickel disilicide (NiSi2) thin film by sputter deposition of NiSi2 is achieved on low-cost and flexible Hastelloy tapes which offers a promising route to fabricate low-cost, flexible electronic devices. Biaxially textured titanium nitride (TiN) is applied as the seeding layer and the diffusion barrier under NiSi2. An epitaxial relationship of (001)⟨100⟩NiSi2 ǁ (001)⟨110⟩TiN is observed with an extra-large lattice mismatch (∼10.3%) between NiSi2 and TiN. Both the bonding similarity and the passivation effect by hydrogen promote the epitaxial growth of NiSi2 on TiN. The flat and smooth NiSi2 thin film consists of grains with a size of 50–100 nm. An epitaxially grown Si film on NiSi2 further demonstrates the potential of manufacturing high-performance Si flexible electronics with NiSi2/TiN/Hastelloy as the direct contact through this approach. [ABSTRACT FROM AUTHOR]