Volume 9 Issue 2, February 2017

Mechanical force applied on the surface of Bi₅Ti₃FeO₁₅ film generates by an AFM tip will effectively drive a transition of the local ferroelastic strain state, reverse both the polarization and magnetization in a way similar to an electric field. Manipulation of both ferroelectric and magnetic domains of Bi₅Ti₃FeO₁₅ thin film using electric field and external mechanical force is reported, which confirms the magnetoelectric coupling in Bi₅Ti₃FeO₁₅, indicates the electric and magnetic orders are coupled through ferroelasticity. Current work provides a framework for exploring cross-coupling among multiple orders and potential for developing novel nanoscale functional devices.

The novel switching behavior is observed in solution-processed silver-doped zinc oxide thin films. This switch exhibited high on-current density of 1 MA cm^-2, ultra-low off-current of 100 fA, excellent thermal stability up to 250 °C, abrupt turn-on with 5 mV per decade and a high on/off ratio of 10⁹. This study demonstrates that the switch devices can be applicable for selectors in ultra-high-density cross-point memory devices with excellent operation margin and extremely low power consumption.

Selective control of vortex structures in closely packed nanodisks with a robust, yet simple, electrode architecture by applying current through electrode.

The complex three-dimensional surface, such as a ‘Venus de Milo’ statue is radiating heat by Joule-heating due to the highly flexible and stretchable copper fibers. The highest temperature can reach up to 328 °C due to self-fused junctions at the copper fiber network.

Radio-frequency (RF) was used to control ultrasound wave propagating through a phononic crystal based metamaterial device. The tunable metamaterial was realized by interstitially filling the spacing in the phononic crystal with high-k, 10% KF doped BaTiO₃ nanoparticles dispersed in poly(N-isopropylacrylamide) (PNIPAM)-based hydrogels. The introduction of high-k nanoparticles enables the hydrogel to have an RF response, thus making a composite with highly variable elastic properties susceptible to RF light. The non-contact mode of applied RF results in a broadening and shift of the transmission spectra resulting in the realization of novel ultrasonic filters and modulators. The RF field also eliminates hybridization and resonance features in the spectra. The metamaterial exhibits tuning of ultrasound waves in both water and air medium.