Binary crystals in two-dimensional two-component Yukawa mixtures

The zero-temperature phase diagram of binary mixtures of particles interacting via a screened Coulomb pair potential is calculated as a function of composition and charge ratio. The potential energy obtained by a Lekner summation is minimized among a variety of candidate two-dimensional crystals. A wealth of different stable crystal structures is identified including $A,B,AB_2, A_2B, AB_4$ structures [$A$ $(B)$ particles correspond to large (small) charge.] Their elementary cells consist of triangular, square or rhombic lattices of the $A$ particles with a basis comprising various structures of $A$ and $B$ particles. For small charge asymmetry there are no intermediate crystals besides the pure $A$ and $B$ triangular crystals.Comment: RevTeX 4 - 17 pages - 6 main figure

Barium manganese(II) selenostannate(IV), BaMnSnSe4

The title compound, BaMnSnSe4, was obtained by reaction of the elements at 1123 K in an evacuated silica tube. It adopts the BaCdSnS4 structure type, which is a variant of the SrIn2Se4 structure type. Its structure consists of distorted edge-sharing tetra­hedra, alternating with Mn and Sn atoms as central atom. These [MnSnSe6] units display corner sharing, forming stacked infinite layers in the ac plane. The three different Ba2+ atoms are located between the [MnSnSe6] layers, two on twofold rotation axes, and exhibit distorted square-antiprismatic coordinations

Glass transition of binary mixtures of dipolar particles in two dimensions

We study the glass transition of binary mixtures of dipolar particles in two dimensions within the framework of mode-coupling theory, focusing in particular on the influence of composition changes. In a first step, we demonstrate that the experimental system of K\"onig et al. [Eur. Phys. J. E 18, 287 (2005)] is well described by point dipoles through a comparison between the experimental partial structure factors and those from our Monte Carlo simulation. For such a mixture of point particles we show that there is always a plasticization effect, i.e. a stabilization of the liquid state due to mixing, in contrast to binary hard disks. We demonstrate that the predicted plasticization effect is in qualitative agreement with experimental results. Furthermore, also some general properties of the glass transition lines are discussed.Comment: 12 pages, 8 figures, J. Non-Cryst. Solids (in print

Stable crystalline lattices in two-dimensional binary mixtures of dipolar particles

The phase diagram of binary mixtures of particles interacting via a pair potential of parallel dipoles is computed at zero temperature as a function of composition and the ratio of their magnetic susceptibilities. Using lattice sums, a rich variety of different stable crystalline structures is identified including $A_mB_n$ structures. [$A$ $(B)$ particles correspond to large (small) dipolar moments.] Their elementary cells consist of triangular, square, rectangular or rhombic lattices of the $A$ particles with a basis comprising various structures of $A$ and $B$ particles. For small (dipolar) asymmetry there are intermediate $AB_2$ and $A_2B$ crystals besides the pure $A$ and $B$ triangular crystals. These structures are detectable in experiments on granular and colloidal matter.Comment: 6 pages - 2 figs - phase diagram update

Ultra-fast quenching of binary colloidal suspensions in an external magnetic field

An ultra-fast quench is applied to binary mixtures of superparamagnetic colloidal particles confined at a two-dimensional water-air interface by a sudden increase of an external magnetic field. This quench realizes a virtually instantaneous cooling which is impossible in molecular systems. Using real-space experiments, the relaxation behavior after the quench is explored. Local crystallites with triangular and square symmetry are formed on different time scales and the correlation peak amplitude of the small particles evolves nonmonotonically in time in agreement with Brownian dynamics computer simulations.Comment: 4 pages, 4 figure

Phygital: Toward the empowerment of the customer and the competitiveness of the retail businesses

With the advent of technology, the retail industry has undergone a significant transformation in the few recent years. Living in the digital era means living in an era where the customers have access to digital tools and information at all times and everywhere. Customers are becoming more tech-oriented, and their expectations are changing rapidly, they also became more demanding regarding many aspects of their shopping experience. And with this free knowledge came the desire to be seen differently, not just the user and the destroyer of goods and services but also an involved stakeholder in the creation process. In response, retailers have been forced to adapt to the new reality and incorporate technology into their businesses. One such adaptation is the concept of phygital - the integration of digital in physical retail spaces, to create a seamless and personalized shopping journey that meets the evolving demands of customers. This article aims to explore, through a critical literature review how the phygital approach can empower customers and make retail businesses more competitive

From Yellow to Black: New Semiconducting Ba Chalcogeno-Germanates

The new germanates Ba 2 GeSe 4−δ Te δ (δ < 2.5) were prepared by reacting the elements under exclusion of air at 800 • C, followed by slow cooling to room temperature. These germanates form the Sr 2 GeS 4 type, monoclinic space group P2 1 /m, with lattice dimensions of a = 699.58(4), b = 709.38(4), c = 917.38(6) pm, β = 109.135(1) • , V = 430.11(4) · 10 6 pm 3 (Z = 2) for Ba 2 GeSe 4 . The structure contains isolated GeSe 4 tetrahedra. The oxidation states are assigned to be Ba II , Ge IV , and Se −II . The yellow color of this ortho-seleno-germanate is indicative of semiconducting behavior with an activation energy of 2.6 -3.0 eV, and the black appearance of the seleno-telluro-germanates points towards gaps < 1.7 eV. Electronic structure calculations based on the LMTO approximation resulted in smaller gaps of 1.7 -0.8 eV, a tendency that is typical for this calculation method

Ultrasonic assisted synthesis, crystallographic, spectroscopic studies and biological activity of three new Zn(II), Co(II) and Ni(II) thiosemicarbazone complexes as precursors for nano-metal oxides

The final publication is available at Elsevier via https://dx.doi.org/10.1016/j.ica.2018.09.054 © 2019. This manuscript version is made available under the CC-BY-NC-ND 4.0 license https://creativecommons.org/licenses/by-nc-nd/4.0/Using ultrasonic irradiations, three new complexes of type [ZnL2].CH3CN, [NiLCl] and [CoL2] (where L is 2-acetylpyridine-4N-p-chlorophenylthiosemicarbazone ligand) have been prepared and investigated using various spectroscopic methods. Crystal structures of ZnL2 and NiLCl complexes displayed distorted octahedral and square-planar coordination geometry around the central metal, respectively. The UV-visible and mass spectroscopic analysis revealed 1:2 (metal:ligand) stoichiometry for Co(II) complex. The synthesized complexes have been used as precursors for preparing their corresponding nano-sized metal oxides via thermal decomposition. The nanostructures of metal oxides were characterized by scanning electron microscope (SEM), energy dispersive X-ray (EDX), X–ray diffraction (XRD) and Fourier transform infrared (FT–IR). The in vitro antibacterial activity of thiosemicarbazone complexes and their corresponding nano-sized metal oxides were studied against a series of gram positive and gram negative bacteria, using the zone inhibition methods. While NiLCl complex was shown to possess more antimicrobial activity than its nano-sized metal oxide, the prepared nano-sized zinc and cobalt oxides have shown the highest activity.University of Guila