Synthesis of Substrate-bound Seaweed-like Au Nanowires with Amino Silane Coupling Agents

Seaweed-like Au nanowires were synthesized without any nanoparticle seeds. The amino silcane coupling agent 3-aminopropyltriethoxysilane was used to form the active surface on Au substrate to facilitate one dimensional growth....

Исследование влияния обработки поверхности Si-подложек на морфологию слоев GaP, полученных методом плазмохимического атомно-слоевого осаждения

Investigations of atomic-layer deposition of GaP layers on Si substrates with different orientations and with different preliminary surface treatment have been carried out. The deposition of GaP was carried out by the method of plasma enhanced atomic-layer deposition using in situ treatment in argon plasma. It was shown that at the initial stage of the growth of GaP layers on precisely oriented (100) Si substrates and with misorientation, two-dimensional growth occurs both after chemical and plasma surface treatment. Upon growth on (111) substrates, after plasma treatment of the surface, a transition to three-dimensional growth is observed, at which the size of islands reaches 30–40 nm. The smallest root-mean-square roughness of the surface of the growing GaP layers (<0.1 nm) was achieved for (100) substrates with a misorientation of 4 °. The GaP layers grown on (100) substrates had a roughness of ~ 0.1 nm, and on substrates with the (111) orientation - 0.12 nm. It was found that the surface treatment of Si substrates with the (100) orientation in hydrogen plasma leads to a slight increase in the surface roughness of growing GaP layers (0.12–0.14 nm), which is associated with the effect of inhomogeneous etching of silicon in hydrogen plasma. When treating the (100) silicon surface in argon plasma, the surface roughness does not change significantly in comparison with the chemical surface treatment. On the surface of substrates with preliminary deposition of an epitaxial Si layer with a thickness of 4 nm, the morphology of GaP layers is the same as in the case of using hydrogen plasma.

High-resolution RHEED analysis of dynamics of low-temperature superstructure transitions in Ge/Si(001) epitaxial system

In this paper, we analyze superstructural transitions during epitaxial growth of two-dimensional layers and the formation of quantum dots by the Stranski–Krastanov mechanism in elastically stressed systems by the reflection high-energy electron diffraction method. Detailed dependences of the periodicity parameter N of the 2 × N reconstruction on the effective thickness of the deposited material in a wide range of growth temperatures during epitaxy of germanium on a silicon surface with a crystallographic orientation (001) are obtained. Superstructural transitions and the change in the value of the parameter N at low temperatures of epitaxy in this system have been investigated for the first time. It is shown that the length of dimer rows in such a reconstruction during the growth of pure germanium on silicon can reach a value of no less than N = 11. A relationship is found between the value of the parameter N, determined by elastic strains in the system, and the critical thickness of the transition from two-dimensional to three-dimensional growth. Based on this relationship, a physical mechanism is proposed that explains the nature of the temperature dependence of the critical thickness of the Stranski–Krastanov transition, which has been the subject of constant scientific disputes until now.

Hierarchical Mg-Birnessite Nanowall Arrays with Enriched (010) Planes for High Performance Aqueous Mg-Ion Batteries

Birnessite MnO2 is a promising cathode material for aqueous Mg-ion batteries due to its layered structure with large interlayer distance. However, the two-dimensional growth mode of birnessite induces nanosheet morphology with preferred growth of inactive (001) planes with sluggish ion transport kinetics. In this work, a high Mg content birnessite with hierarchical nanowall arrays morphology is prepared by in situ electro-conversion using spinel Mn3O4 nanowall arrays. The electro-conversion Mg-birnessite (ECMB) nanowall arrays are assembled by ultrasmall nanosheets with reduced (001) planes but increased active (010) planes, affording enriched open intercalation channels and shortened Mg2+ diffusion length. Consequently, the ECMB cathode exhibits a large specific reversible capacity of about 255.1 mAh/g at a current density of 200 mA/g, and outstanding cycling stability with 73.6% capacity retention after 3000 cycles. Finally, a 2.2 V aqueous full cell is constructed by using ECMB as positive electrode and polyimide as negative electrode, which achieves a high energy density of 65.2 Wh/kg at a power density of 96 W/kg. This work demonstrates effective crystal plane modulation for Mg-birnessite to achieve superior Mg2+ storage in aqueous batteries.

Analyzing Factors Inhibiting the Growth of the Church According to the Apostles and Their Relevance to the Challenges of the Church Today

Church growth is a phenomenon that is very commonly discussed by people, especially in the Christian world. Often church growth is seen from the quantity (the number of congregations growing rapidly and many) without regard to the quality of the congregation. Although the Bible does not specifically talk about church growth, the principle of church growth is understood in the words of Jesus "I will build my church and the gates of hell will not overpower it", (Matt. 16:18), the church can live and grow even though the number of membership / attendance do not change. According to Rick Warren, healthy church growth is multi-dimensional growth, namely a church that grows closer to each other through fellowship, grows more earnestly through discipleship, and grows stronger through worship (Waren, 2019). He further said that the growth of the church is the result of a healthy natural where the preaching of the Bible and the mission carried out are balanced. In the church there are factors that inhibit church growth, namely: quantitative factors, qualitative factors, organic factors, historical trauma factors, theological misunderstanding factors, religious factors. For this reason, the Church must experience changes in dealing with any situation and influence the world. The church can not only rotate in one place. The church must make a difficult change, namely by preaching the gospel of salvation to those in need, in order to be saved. The church must make new breakthroughs in an increasingly changing world.

Self-catalytic growth of one-dimensional materials within dislocations in gold

Dislocations in metals affect their properties on the macro- and the microscales. For example, they increase a metal’s hardness and strength. Dislocation outcrops exist on the surfaces of such metals, and atoms in the proximity of these outcrops are more loosely bonded, facilitating local chemical corrosion and reactivity. In this study, we present a unique autocatalytic mechanism by which a system of inorganic semiconducting gold(I) cyanide nanowires forms within preexisting dislocation lines in a plastically deformed Au-Ag alloy. The formation occurs during the classical selective dealloying process that forms nanoporous Au. Nucleation of the nanowire originates at the surfaces of the catalytic dislocation outcrops. The nanowires are single crystals that spontaneously undergo layer-by-layer one-dimensional growth. The continuous growth of nanowires is achieved when the dislocation density exceeds a critical value evaluated on the basis of a kinetic model that we developed.