Auxetic piezoelectric effect in heterostructures.

Inherent symmetry breaking at the interface has been fundamental to a myriad of physical effects and functionalities, such as efficient spin-charge interconversion, exotic magnetic structures and an emergent bulk photovoltaic effect. It has recently been demonstrated that interface asymmetry can induce sizable piezoelectric effects in heterostructures, even those consisting of centrosymmetric semiconductors, which provides flexibility to develop and optimize electromechanical coupling phenomena. Here, by targeted engineering of the interface symmetry, we achieve piezoelectric phenomena behaving as the electrical analogue of the negative Poisson's ratio.

Photoinduced Negative Differential Resistivity and Gunn Oscillations in SrTiO3.

SrTiO , a perovskite oxide, holds significant potential for application in the field of oxide electronics. Notably, its photoelectric activity in the low temperature regime, which overlaps with the quantum paraelectric state, exhibits remarkable characteristics. In this study, it is demonstrated that when photo-excited with above band gap energy photons, SrTiO exhibits non-linear transport of photocarriers and voltage-controlled negative resistance, resulting from an intervalley transfer of photo-induced electrons.

Acquired benign tracheo‑oesophageal fistula secondary to oesophageal stenting for post lye ingestion stenosis: A case report.

Acquired benign trachea-oesophageal fistula is a rare benign pathological entity with varying aetiologies that most often occurs post-intubation. This case report presents the case of a female patient, 31 years old, admitted to the emergency room with sepsis syndrome following bilateral aspiration pneumonia caused by a large trachea-oesophageal fistula. The fistula was the result of intra-tracheal migration of an oesophageal stent placed for post lye ingestion stenosis.

Bond engineering of molecular ferroelectrics renders soft and high-performance piezoelectric energy harvesting materials.

Piezoelectric materials convert mechanical stress to electrical energy and thus are widely used in energy harvesting and wearable devices. However, in the piezoelectric family, there are two pairs of properties that improving one of them will generally compromises the other, which limits their applications. The first pair is piezoelectric strain and voltage constant, and the second is piezoelectric performance and mechanical softness.

Enhanced Photoconductivity at Dislocations in SrTiO.

Dislocations are 1D crystallographic line defects and are usually seen as detrimental to the functional properties of classic semiconductors. It is shown here that this not necessarily accounts for oxide semiconductors in which dislocations are capable of boosting the photoconductivity. Strontium titanate single crystals are controllably deformed to generate a high density of ordered dislocations of two slip systems possessing different mesoscopic arrangements.