Ultrahigh electromechanical response from competing ferroic orders.

Materials with electromechanical coupling are essential for transducers and acoustic devices as reversible converters between mechanical and electrical energy. High electromechanical responses are typically found in materials with strong structural instabilities, conventionally achieved by two strategies-morphotropic phase boundaries and nanoscale structural heterogeneity. Here we demonstrate a different strategy to accomplish ultrahigh electromechanical response by inducing extreme structural instability from competing antiferroelectric and ferroelectric orders.

Multicolor x-rays from free electron-driven van der Waals heterostructures.

The emergence of van der Waals (vdW) heterostructures has led to precise and versatile methods of fabricating devices with atomic-scale accuracies. Hence, vdW heterostructures have shown much promise for technologies including photodetectors, photocatalysis, photovoltaic devices, ultrafast photonic devices, and field-effect transistors. These applications, however, remain confined to optical and suboptical regimes.

Synergistic use of gradient flipping and phase prediction for inline electron holography.

Inline holography in the transmission electron microscope is a versatile technique which provides real-space phase information that can be used for the correction of imaging aberrations, as well as for measuring electric and magnetic fields and strain distributions. It is able to recover high-spatial-frequency contributions of the phase effectively but suffers from the weak transfer of low-spatial-frequency information, as well as from incoherent scattering. Here, we combine gradient flipping and phase prediction in an iterative flux-preserving focal series reconstruction algorithm with incoherent background subtraction that gives extensive access to the missing low spatial frequencies.