Metadielectrics for high-temperature energy storage capacitors.

Dielectric capacitors are highly desired for electronic systems owing to their high-power density and ultrafast charge/discharge capability. However, the current dielectric capacitors suffer severely from the thermal instabilities, with sharp deterioration of energy storage performance at elevated temperatures. Here, guided by phase-field simulations, we conceived and fabricated the self-assembled metadielectric nanostructure with HfO as second-phase in BaHfTiO relaxor ferroelectric matrix.

Electron beam lithography of GeTe through polymorphic phase transformation.

We report two previously undiscovered phases of GeTe including the sphalerite (c-) phase and the hexagonal (h-) phase with interlayer van der Waals gaps. A polymorphic phase transformation from rhombohedral α-GeTe to c- and h-GeTe at near room temperature is first realized electron beam irradiation. Their underlying thermodynamics and kinetics are illustrated using the heating experiments and molecular dynamics simulations.

Multiscale Structural Engineering Boosts Piezoelectricity in NaBiNbO-Based High-Temperature Piezoceramics.

High-temperature piezoelectric materials, which enable the accurate and reliable sensing of physical parameters to guarantee the functional operation of various systems under harsh conditions, are highly demanded. To this end, both large piezoelectricity and high Curie temperature are pivotal figures of merit (FOMs) for high-temperature piezoceramics. Unfortunately, despite intensive pursuits, it remains a formidable challenge to unravel the inverse correlation between these FOMs.

Nanoscale fabrication of heterostructures in thermoelectric SnTe.

Enhancing the performance of thermoelectric materials is demanded to develop strategies for introducing multidimensional microstructures into materials to induce full-scale phonon scattering while ensuring electrical transport performance. Herein, a previously unreported rhombohedral h-SnTe (3̄) has been achieved in the nanoscale dimension by the electron beam irradiation of β-SnTe (3̄) materials. The h-SnTe structure contains interlayer van der Waals gaps and exhibits metallic behavior evaluated by density-functional theory calculations, which coherently appears in the narrow-band semiconductor β-SnTe matrix.

Interfacial Modulation on CoFeO Epitaxial Thin Films for Anomalous Hall Sensor Applications.

Magnetic oxide films with a strong anomalous Hall effect (AHE) have attracted much attention due to their strong sensitivity and high polarization for magnetic sensor applications. However, the linearity of the anomalous Hall sensors still needs improving. In this work, we propose to use the interface regulation to improve the linearity of the AHE.

Revealing self-aligned γ-SnTe ultrathin nanosheets in thermoelectric β-SnTe.

An atomic-scale understanding of nanoscale precipitates in thermoelectric materials will help us explore their microstructure-property relationship, providing a strategy to optimize their thermoelectric properties. In thermoelectric β-SnTe, using advanced electron microscopy techniques, self-aligned nanoscale precipitates have been identified as γ-SnTe ultrathin nanosheets that induce anisotropic strain in the β-SnTe matrix. The interlayer van der Waals interactions occur across the interface of γ-SnTe ultrathin nanosheets and the β-SnTe matrix.

Self-assembling behavior and interface structure in vertically aligned nanocomposite (PrBaMnO):(CeO) films on (001) (La,Sr)(Al,Ta)O substrates.

Heteroepitaxial oxide-based nanocomposite films possessing a variety of functional properties have attracted tremendous research interest. Here, self-assembled vertically aligned nanocomposite (PrBaMnO):(CeO) (x = 0.2 and 0.

B-site ordering and strain-induced phase transition in double-perovskite LaNiMnO films.

The magnetic and electrical properties of complex oxide thin films are closely related to the phase stability and cation ordering, which demands that we understand the process-structure-property relationships microscopically in functional materials research. Here we study multiferroic thin films of double-perovskite LaNiMnO epitaxially grown on SrTiO, KTaO, LaAlO and DyScO substrates by pulsed laser deposition. The effect of epitaxial strains imposed by the substrate on the microstructural properties of LaNiMnO has been systematically investigated by means of advanced electron microscopy.

Formation of Ruddlesden-Popper Faults and Their Effect on the Magnetic Properties in PrSrCoO Thin Films.

Epitaxial PrSrCoO thin films have been grown on single-crystalline (LaSr)(AlTa)O(001) substrates by the pulsed laser deposition technique. The magnetic properties and microstructure of these films are investigated. It is found that Ruddlesden-Popper faults (RP faults) can be introduced in the films by changing the laser repetition rate.