Graphene of 1–5 layers was synthesized on a polycrystalline Co film by radio-frequency plasma-enhanced chemical vapour deposition at a relatively low temperature of 800 °C for only 40 s in a mixture of gases of CH4/H2/Ar (1/5/20, with a total gas flow rate of 78 sccm). The obtained graphene is of high quality as revealed by Raman spectroscopy and x-ray photoelectron spectroscopy. It exhibits a high optical transmittance of more than 70% in the wavelength range 500–1200 nm, and a sheet resistivity of 2661 Ω/sq. A possible formation mechanism is proposed. The significant influence of octahedral and tetrahedral lattice interstitial sites in the Co crystallites on the formation of graphene is discussed.

Cuprous oxide films were successfully electrodeposited onto three different substrates through the reduction of copper lactate in alkaline solution at pH = 10. The substrates include indium tin oxide film coated glass, n-Si wafer with (001) orientation and Au film evaporated onto Si substrate. The substrate effects on the structural and optical properties of the electrodeposited films are investigated by in situ voltammetry, current versus time transient measurement, ex situ x-ray diffraction, scanning electron microscopy, UV-vis transmittance and reflectance and photoluminescence techniques. The results indicate that the choice of substrate can strongly affect the film morphology, structure and optical properties.

A study on the unipolar resistive switching of a CoO thin film shows that the compliance current (CC) has strong effects on the local structure of conducting filaments (CFs). Lower CCs produce CFs with simple connectivity and good controllability, resulting in a narrow distribution of switching voltages (SVs) and a high ratio of high-to-low resistance states. In contrast, the stronger net-like CFs are formed at higher CCs, and their complete rupture is difficult. Thus, the lower high-resistance states and a wide distribution of SVs appear in the reversible switching processes. Our results suggest that the generation of CFs with simple local structures is as important as the rupture process.