Proton Migration on the Boron Sheets Surface

Borophene is a two-dimensional allotrope of boron and it is also known as boron sheet. First it has been predicted theoretically in the mid-1990s, experimentally borophene was confirmed in 2015 when the structure was successfully synthesized in 2015. One of the key features of borophene is its strong anisotropy – the dependence of mechanical and electrical properties on direction. This phenomenon is not typical for 2D materials and has never been observed in 2D metals before. Borophene has the highest tensile strength of all known two-dimensional materials. In early works, it was found that the adsorption of a hydrogen atom on the surface of borophene is possible and the analyses of electronic density showed that atom H became a proton. Therefore, in this work, the authors have studied the proton migration over the surface of boron sheets of two types and have found the most energetically favorable path of proton motion. The electron-energy characteristics of the process of migration of a single proton along the surface of boron layers of two types are determined and it is established that in all the considered cases the proton is able to move along the surface almost barrier-free. The type of conductivity of pure boron layers and layers modified by a single proton is determined. In the A-type boron layer, the proton increases the band gap by 0.04 eV, and in the B-type layer, the band gap changes by 0.05 eV. It is proved that two-dimensional boron nanostructures can be considered as a new class of boron topological structure with proton conductivity.

Half-Auxeticity and Anisotropic Transport in Pd Decorated Two-Dimensional Boron Sheets

<p></p><p>If one strains a material, most materials shrink normal to the direction of applied strain. Similarly, if a material is compressed, it will expand in the direction orthogonal to the pressure. Few materials, those of negative Poisson ratio, show the opposite behavior. Here, we show an unprecedented feature, a material that expands normal to the direction of stress, regardless if it is strained or compressed. Such behavior, namely, half-auxeticity, is demonstrated for a borophene sheet stabilized by decorating Pd atoms. We explore Pd-decorated borophene, identify three stable phases of which one has this peculiar property of half auxeticity. After carefully analyzing stability, mechanical and electronic properties we explore the origin of this very uncommon behavior and identify it as a structural feature that may also be employed to design further 2D nanomaterials.</p><br><p></p>

Half-Auxeticity and Anisotropic Transport in Pd Decorated Two-Dimensional Boron Sheets

<p>If one strains a material, most materials shrink normal to the direction of applied strain. Similarly, if a material is compressed, it will expand in the direction orthogonal to the pressure. Few materials, those of negative Poisson ratio, show the opposite behavior. Here, we show an unprecedented feature, a material that expands normal to the direction of stress, regardless if it is strained or compressed. Such behavior, namely half-auxeticity, is demonstrated for a borophene sheet stabilized by decorating Pd atoms. We explore Pd-decorated borophene, identify three stable phases of which one has this peculiar property of half auxeticity. After carefully analyzing stability, mechanical and electronic properties we explore the origin of this very uncommon behavior, and identify it as a structural feature that may also be employed to design further 2D nanomaterials.</p><br>

Half-Auxeticity and Anisotropic Transport in Pd Decorated Two-Dimensional Boron Sheets

<p>If one strains a material, most materials shrink normal to the direction of applied strain. Similarly, if a material is compressed, it will expand in the direction orthogonal to the pressure. Few materials, those of negative Poisson ratio, show the opposite behavior. Here, we show an unprecedented feature, a material that expands normal to the direction of stress, regardless if it is strained or compressed. Such behavior, namely half-auxeticity, is demonstrated for a borophene sheet stabilized by decorating Pd atoms. We explore Pd-decorated borophene, identify three stable phases of which one has this peculiar property of half auxeticity. After carefully analyzing stability, mechanical and electronic properties we explore the origin of this very uncommon behavior, and identify it as a structural feature that may also be employed to design further 2D nanomaterials.</p><br>

Half-Auxeticity and Anisotropic Transport in Pd Decorated Two-Dimensional Boron Sheets

If one strains a material along a direction, most materials shrink normal to that direction. Similarly, if you compress the material, it will expand in the direction orthogonal to the pressure. Few materials, those of negative Poisson ratio, show the opposite behavior. Here, we show an unprecedented feature, a material that expands normal to the direction of force regardless if it is strained or compressed. Such behavior, called half-auxeticity, has been found for a borophene sheet stabilized by decorating Pd atoms. Herein, we explore Pd-decorated borophene, identify three stable phases of which one has this peculiar property of half auxeticity. After carefully analyzing stability, mechanical and electronic properties we explore the origin of this very uncommon behavior.<br>

Polymorphism of low dimensional boron nanomaterials driven by electrostatic gating: a computational discovery

We discovered the structural diversity of 2D boron sheets and 1D ribbons triggered by electrostatic gating.