The coalescence of twins in bismuth single crystals

The process of the coalescence of twin boundaries in bismuth single crystals has been studied. It has been established that the twin coalescence can occur without the formation of an interface between them or with the formation of a double twin boundary, depending on the direction of twin growth and orientation of twinning planes.     

Lanthanum oxide nanostructured films synthesized using hot dense and extremely non-equilibrium plasma for nanoelectronic device applications

Lanthanum oxide (La₂O₃) nanostructured films are synthesized on a p-type silicon wafer by ablation of La₂O₃ pellet due to interaction with hot dense argon plasmas in a modified dense plasma focus (DPF) device. The nanostructured films are investigated using scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray diffraction (XRD) spectra. SEM study shows the formation of nano-films having nano-size structures with the average nanostructures size ~25, ~53, and ~45 nm for one, two, and three DPF shots, respectively. The nanostructures sizes and morphology of nano-films are consistent between the AFM and SEM analyses. XRD spectra confirms nano-sized La₂O₃ with an average grain size ~34, ~51, and ~42 nm for one, two, and three DPF shots, respectively. The electrical properties such as current–voltage and capacitance–voltage (C–V) characteristics of the Al–La₂O₃–Si metal–oxide–semiconductor (MOS) capacitor structure are measured. The current conduction mechanism of the MOS capacitors is also demonstrated. The C–V characteristics are further used to obtain the electrical parameters such as the dielectric constant, oxide thickness, flat-band capacitance, and flat-band voltage of the MOS capacitors. These measurements demonstrate significantly lower leakage currents without any commonly used annealing or doping, thereby revealing a significant improvement of the MOS nanoelectronic device performance due to the incorporation of the DPF-produced La₂O₃ nano-films.     

Beyond Seashells: Bioinspired 2D Photonic and Photoelectronic Devices

The discovery of novel materials that possess extraordinary optical properties are of special interest, as they inspire systems for next‐generation solar energy harvesting and conversion devices. Learning from nature has inspired the development of many photonic nanomaterials with fascinating structural colors. 2D photonic nanostructures, inspired by the attractive optical properties found on the inner surfaces of seashells, are fabricated in a facile and scalable way. The shells generate shining clusters for preying on phototactic creatures through interaction with incident solar light in water. By alternately depositing graphene and 2D ultrathin TiO₂ nanosheets to form 2D–2D heterostructures and homostructures, seashell‐inspired nanomaterials with well‐controlled parameters are successfully achieved. They exhibit exceptional interlayer charge transfer properties and ultrafast in‐plane electron mobility and present fascinating nacre‐mimicking optical properties and significantly enhanced light‐response behavior when acting as photoelectrodes. A window into the fabrication of novel 2D photonic structures and devices is opened, paving the way for the design of high‐performance solar‐energy harvesting and conversion devices.     

Nanosphere monolayer-templated, ion-assisted nanofeature etching in dielectric materials: a numerical simulation of nanoscale ion flux topography

The results of numerical simulations of nanometer precision distributions of microscopic ion fluxes in ion-assisted etching of nanoscale features on the surfaces of dielectric materials using a self-assembled monolayer of spherical nanoparticles as a mask are presented. It is shown that the ion fluxes to the substrate and nanosphere surfaces can be effectively controlled by the plasma parameters and the external bias applied to the substrate. By proper adjustment of these parameters, the ion flux can be focused onto the areas uncovered by the nanospheres. Under certain conditions, the ion flux distributions feature sophisticated hexagonal patterns, which may lead to very different nanofeature etching profiles. The results presented are generic and suggest viable ways to overcome some of the limitations of the existing plasma-assisted nanolithography.     

Effect of irradiation by boron ions on the character of realization of twinning and slip under prolonged (more than 60 sec) loading of single crystals of bismuth

The twinning of single crystals of bismuth irradiated by boron ions with an energy of 25 keV and a dose of 10¹⁷ ion/cm², in the case of prolonged (more than 60 sec) loading of a crystal is studied. It is found that prolonged exposure of a crystal to a concentrated load promotes a decrease in the number of twins in the concentrator of external stresses. An increase of temperature up to 400 K stimulates the process of slip in the realization of plastic deformation of a crystal. Mozyr’ State Pedagogical Institute, Mozyr’, Belarus. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 72, No. 5, pp. 967–970.