We proposed 3D architectures of complex oxides as a way to derive novel properties: various 3D shapes were formed by self-shaped free-standing membranes, and curvature-induced polarization in an otherwise nonpolar material was observed.
A rapid heating rate (∼110 °C s−1) allows strain energy to maximally build up in the YSZ layer at the annealing temperature, and the defects are effectively annihilated during annealing.
We report the epitaxial
growth of (2̅01)-oriented
β-Ga2O3 thin films on a (001) Si substrate
using the
pulsed laser deposition technique employing epitaxial yttria-stabilized
zirconia (YSZ) buffer layers. Epitaxial β-Ga2O3 thin films possess a biaxial compressive strain on YSZ single-crystal
substrates while they exhibit a biaxial tensile strain on YSZ-buffered
Si substrates. Post-annealing improves the crystalline quality of
β-Ga2O3 thin films. High-resolution X-ray
diffraction analyses reveal that the epitaxial (2̅01) β-Ga2O3 thin films on Si have eight in-plane domain
variants to accommodate the large difference in the crystal structure
between monoclinic β-Ga2O3 and cubic YSZ.
The results provide a pathway to integrate epitaxial β-Ga2O3 thin films on a Si gold standard substrate,
which will expand the application scope beyond high-power electronics.
Dual-frequency ultrasound has advantages over conventional ultrasound, which operates at a specific frequency band, due to its additional frequency response. Moreover, a tunable frequency from a single transducer enables sonographers to achieve ultrasound images with a large detection area and high resolution. This facilitates the availability of more advanced techniques that require low- and high frequency ultrasound simultaneously such as harmonic imaging and image-guided therapy. In this article, we present a novel method for dual-frequency ultrasound generation from a ferroelectric piezoelectric micromachined ultrasound transducer (PMUT). Uniformly designed transducer arrays can be used for both deep low-resolution imaging and shallow high-resolution imaging. To switch the ultrasound frequency, the only requirement is to tune a DC bias for controlling the polarization state of the ferroelectric film. Flextensional vibration of the PMUT’s membrane strongly depends on the polarization state, producing low- and high-frequency ultrasound from a single excitation frequency. This strategy for dual-frequency ultrasound dispenses with the requirement for either multi-electrode configurations or hetero-designed elements, which are integrated into an array. Consequently, this technique significantly reduces the design complexity of transducer arrays and their associated driving circuits.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.