Induced magnetic states upon electron-hole injection at B and N sites of hexagonal Boron Nitride bilayer: A DFT study

We have reported the electronic, magnetic, and optical properties of the top layer carbon-doped hexagonal Boron Nitride(h-BN) bilayer at B/N-sites using the density functional theory implemented in Quantumwise VNL-ATK package. The calculated structural and electronic properties of the h-BN bilayer are in agreement with the previously reported results. A single carbon doping on B and N sites modifies the large band gap semiconducting behaviour of h-BN bilayer similar to dilute magnetic semi-conducting material with a net magnetic moment of 1.001 μ B and 0.998 μ B , respectively. For double doping at B/N sites net magnetic moment increases to 1.998 μ B and 1.824 μ B , respectively. Whereas for triply carbon doped bilayer system at B/N sites, the system changes to metallic behaviour. Upon carbon doping at N-site, we obtained transition from Non-Magnetic semiconductor(Pristine) → Magnetic semiconductor(1C) → Half-Metal ferromagnetic(2C) → Metal(3C). Whereas, in case of doping at the B-site, we observed transition from Non-Magnetic Semiconductor(Pristine) → Magnetic Semiconductor(1C) → Metal (2C, 3C). Analysis from the PDOS plot of the car- bon doped systems reveals that the net magnetic moments are contributed by the 2p orbitals of carbon and partial contribution from the neighboring nitrogen and boron atoms, respectively. As 1,2C doping at the B-site reduces the energy band gap to 0.81-1.8 eV which falls in the visible spectrum and thus such system further opens up an opportunity to be utilised as a photocatalys material. Our carbon doped systems show a magnetic semiconducting behavior with a nite magnetic moment which is one of the criteria for a spintronic material. So, our system looks promising in this regard. Also, Carbon doping can be considered as a simple approach to tune the band gap of the Boron Nitride bilayer system.

Sodium Solid Electrolytes: NaxAlOy Bilayer-System Based on Macroporous Bulk Material and Dense Thin-Film

A new preparation concept of a partially porous solid-state bilayer electrolyte (BE) for high-temperature sodium-ion batteries has been developed. The porous layer provides mechanical strength and is infiltrated with liquid and highly conductive NaAlCl4 salt, while the dense layer prevents short circuits. Both layers consist, at least partially, of Na-β-alumina. The BEs are synthesized by a three-step procedure, including a sol-gel synthesis, the preparation of porous, calcined bulk material, and spin coating to deposit a dense layer. A detailed study is carried out to investigate the effect of polyethylene oxide (PEO) concentration on pore size and crystallization of the bulk material. The microstructure and crystallographic composition are verified for all steps via mercury intrusion, X-ray diffraction, and scanning electron microscopy. The porous bulk material exhibits an unprecedented open porosity for a NaxAlOy bilayer-system of ≤57% with a pore size of ≈200–300 nm and pore volume of ≤0.3 cm3∙g−1. It contains high shares of crystalline α-Al2O3 and Na-β-alumina. The BEs are characterized by impedance spectroscopy, which proved an increase of ionic conductivity with increasing porosity and increasing Na-β-alumina phase content in the bulk material. Ion conductivity of up to 0.10 S∙cm−1 at 300 °C is achieved.

Embedded Interface Regulates Underwater Actuation of Solvent-Responsive Soft Grippers

In this work, we report the role of an embedded interface between two polymer thin films in determining the overall folding and actuation characteristics of a bilayer system applied for...