ABSTRACT
Highly transparent indium-free multilayers of TiO2/Cu/TiO2 were obtained by means of annealing. The effects of Cu thickness and annealing temperature on the electrical and optical properties were investigated. The critical thickness of Cu mid-layer with optimal electrical and optical properties was 10 nm, with the figure of merit reaching as high as 5 × 10-3 Ω-1. Partial crystallization of the TiO2 layer enhanced the electrical and optical properties upon annealing. Electrothermal experiments showed that temperatures of more than 100 °C can be reached at a heating rate of 2 °C/s without any damage to the multilayers. The experimental results indicate that reliable transparent TiO2/Cu/TiO2 multilayers can be used for electrothermal application.
ABSTRACT
We report a potential way to enhance and tune the multiferroic and resistive switching properties of BiFeO3 nanoparticles through dilute aliovalent Li(1+) doping (0.046 atomic percent) at the Fe(3+) sites of BiFeO3. The high purity of the samples and the extent of doping were confirmed by different physical characterizations. Enhanced multiferroic properties with a magnetic moment per Fe atom ≈ 0.12 µB and electric polarization ≈ 49 µC cm(-2) were observed in one of the Li(1+) doped samples. A phenomenological model has been proposed to support the observed magnetic behavior of the doped samples. From a potential application point of view, we further report on the doping concentration and polarization coercivity dependent highly stable resistive switching behavior (endurance cycles >10(3) and stability >10(6) s) of Li-doped BiFeO3 nanoparticles. The stable complementary resistive switching behavior (1 bit operation) for >50 cycles and under voltage pulse for 10(3) cycles in the doped BiFeO3 at a low operating bias is reported. Thus, dilute aliovalent Li(1+) doping enables tunability of the ferroic and resistive switching properties of BiFeO3and shows it to be a promising multiferroic material.
