Heterodimensional superlattice with in-plane anomalous Hall effect.

Superlattices-a periodic stacking of two-dimensional layers of two or more materials-provide a versatile scheme for engineering materials with tailored properties1,2. Here we report an intrinsic heterodimensional superlattice consisting of alternating layers of two-dimensional vanadium disulfide (VS2) and a one-dimensional vanadium sulfide (VS) chain array, deposited directly by chemical vapour deposition. This unique superlattice features an unconventional 1T stacking with a monoclinic unit cell of VS2/VS layers identified by scanning transmission electron microscopy. An unexpected Hall effect, persisting up to 380 kelvin, is observed when the magnetic field is in-plane, a condition under which the Hall effect usually vanishes. The observation of this effect is supported by theoretical calculations, and can be attributed to an unconventional anomalous Hall effect owing to an out-of-plane Berry curvature induced by an in-plane magnetic field, which is related to the one-dimensional VS chain. Our work expands the conventional understanding of superlattices and will stimulate the synthesis of more extraordinary superstructures.

Chemical Vapor Deposition of Superconducting FeTe1-xSex Nanosheets.

FeTe1-xSex, a promising layered material used to realize Majorana zero modes, has attracted enormous attention in recent years. Pulsed laser deposition (PLD) and molecular-beam epitaxy (MBE) are the routine growth methods used to prepare FeTe1-xSex thin films. However, both methods require high-vacuum conditions and polished crystalline substrates, which hinder the exploration of the topological superconductivity and related nanodevices of this material. Here we demonstrate the growth of the ultrathin FeTe1-xSex superconductor by a facile, atmospheric pressure chemical vapor deposition (CVD) method. The composition and thickness of the two-dimensional (2D) FeTe1-xSex nanosheets are well controlled by tuning the experimental conditions. The as-prepared FeTe0.8Se0.2 nanosheet exhibits an onset superconducting transition temperature of 12.4 K, proving its high quality. Our work offers an effective strategy for preparing the ultrathin FeTe1-xSex superconductor, which could become a promising platform for further study of the unconventional superconductivity in the FeTe1-xSex system.

[Preliminary study on premixed materials of emulsion gel].

The purpose of this paper was to study the pre-mixed materials of emulsion gel. Accessories were screened and formula was designed with the most common use, low cost and simple process as the standards. Experiments were designed by central composite design-response surface methodology (ccd-rsm). 8.0.6 Trial Design-Expert was used for data processing and analysis, and subjective scores were used as the index to draw the three-dimensional effect surface and 2D contour maps. It was determined that the optimal ranges were A (carbomer 940)： 0.05-0.065 g; B (castor oil)： 1.00-1.12 mL; C (poly polysorbate-80)： 0.15 mL. The optimal formula was as follows： carbopol 0.057 5 g, castor oil 1.1 mL, polysorbate-80 0.15 mL. The formulated substrate was studied on its preliminary stability and rheology characteristics, such as viscosity and thixotropy. Then with the optimal formula as substrate, emulsion type gel was prepared respectively with 98% rutin, 98% berberine hydrochloride, and 98% berbamine hydrochloride as the main component. With 0.9% normal saline as the absorption solution, the results showed that the ransdermal flux of the three formulations of 1 h was all less than 1%. The results indicated that this substrate had the potential to be developed into a premixed material. The emulsion type gel matrix made from this formula had a good appearance, stability to certain extent, appropriate viscosity and thixotropy, and showed no skin irritation in 1 h.