Noninvasive Embedding of Single Co Atoms in Ge(111)2x1 Surfaces

We report on a combined scanning tunneling microscopy (STM) and density functional theory (DFT) based investigation of Co atoms on Ge(111)2x1 surfaces. When deposited on cold surfaces, individual Co atoms have a limited diffusivity on the atomically flat areas and apparently reside on top of the upper pi-bonded chain rows exclusively. Voltage-dependent STM imaging reveals a highly anisotropic electronic perturbation of the Ge surface surrounding these Co atoms and pronounced one-dimensional confinement along the pi-bonded chains. DFT calculations reveal that the individual Co atoms are in fact embedded in the Ge surface, where they occupy a quasi-stationary position within the big 7-member Ge ring in between the 3rd and 4th atomic Ge layer. The energy needed for the Co atoms to overcome the potential barrier for penetration in the Ge surface is provided by the kinetic energy resulting from the deposition process. DFT calculations further demonstrate that the embedded Co atoms form four covalent Co-Ge bonds, resulting in a Co4+ valence state and a 3d5 electronic configuration. Calculated STM images are in perfect agreement with the experimental atomic resolution STM images for the broad range of applied tunneling voltages.Comment: 19 pages, 15 figures, 3 table

Low-temperature scanning tunneling microscopy of ring-like surface electronic structures around Co islands on InAs(110) surfaces

We report on the experimental observation by scanning tunneling microscopy at low temperature of ring-like features that appear around Co metal clusters deposited on a clean (110) oriented surface of cleaved p-type InAs crystals. These features are visible in spectroscopic images within a certain range of negative tunneling bias voltages due to the presence of a negative differential conductance in the current-voltage dependence. A theoretical model is introduced, which takes into account non-equilibrium effects in the small tunneling junction area. In the framework of this model the appearance of the ring-like features is explained in terms of interference effects between electrons tunneling directly and indirectly (via a Co island) between the tip and the InAs surface.Comment: 8 pages, 4 figure

Концентрація ТБК-активних продуктів у плазмі крові щурів при розвитку та гальмуванні росту карциноми герена

Content of TBA-active products in rat’s blood plasma was investigated during the Guerin carcinoma development and introduction of cis-platine and cluster Rhenium substances with organic ligands. It was shown that Rhenium substances had essential antioxidant effects and changed the dynamics of a tumor growth. It was drawn the conclusion on importance of further in vivo experimental investigations of the Rhenium substances with cluster fragment and organic ligands in an organism of changed redox state.Досліджено вміст ТБК-активних продуктів у плазмі крові щурів при розвитку карциноми Герена Т8, введенні цис-платину та кластерних сполук ренію з органічними лігандами. Показано, що сполуки ренію мають значний антиоксидантний ефект і змінюють динаміку розвитку пухлини. Зроблено висновок про перспективність використання сполук ренію, які містять кластерний фрагмент і органічні ліганди, для подальших досліджень in vivo при зміненому редокс-статусі організму.Досліджено вміст ТБК-активних продуктів у плазмі крові щурів при розвитку карциноми Герена Т8, введенні цис-платину та кластерних сполук ренію з органічними лігандами. Показано, що сполуки ренію мають значний антиоксидантний ефект і змінюють динаміку розвитку пухлини. Зроблено висновок про перспективність використання сполук ренію, які містять кластерний фрагмент і органічні ліганди, для подальших досліджень in vivo при зміненому редокс-статусі організму

Initial Stage of Ge growth on Au(111) surface

В данной работе изучен процесс абсорбции германия на поверхности Au(111) и проведен анализ особенностей роста сформированных структур методом СТМ. При напылении на холодную подложку формируется аморфный слой. При напылении на нагретую подложку обнаружены несколько типов кристаллических структур.We investigate absorption of Ge atoms on Au(111) surface and the formed structures are analyzed via STM. Germanium deposited on a room temperature substrate forms an amorphous layer. In case of deposition on the hot substrate we observe several types of crystalline structures.Работа была поддержана грантом РФФИ №16-02-00818_а

The embedding of transnational entrepreneurs in diaspora networks:Leveraging the assets of foreignness

In this paper we examine how foreign actors capitalize on their ethnic identity to gain skills and capabilities that enable them to operate in a new and strange environment. We explore the mechanisms by which Bulgarian entrepreneurs in London use their ethnic identity to develop competitive advantage and business contacts. We find that the entrepreneurs studied gain access to a diaspora network, which enables them to develop essential business capabilities and integrate knowledge from both home and host country environments. The diaspora community possesses a collective asset (transactive memory) that allows its members to remove competition from the interfirm level to the network level (i.e., diaspora networks vs. networks of native businesspeople). Additionally, the cultural identity and networks to which community members have access provide bridging capabilities that allow diaspora businesspeople to make links to host country business partners and thus embed themselves in the host country environment. Thus, this paper adds to the growing body of work showing how foreignness can serve as an asset in addition to its better-known role as a liability

Electronically decoupled stacking fault tetrahedra embedded in Au(111) films

Stacking faults are known as defective structures in crystalline materials that typically lower the structural quality of the material. Here, we show that a particular type of defect, that is, stacking fault tetrahedra (SFTs), exhibits pronounced quantized electronic behaviour, revealing a potential synthetic route to decoupled nanoparticles in metal films. We report on the electronic properties of SFTs that exist in Au(111) films, as evidenced by scanning tunnelling microscopy and confirmed by transmission electron microscopy. We find that the SFTs reveal a remarkable decoupling from their metal surroundings, leading to pronounced energy level quantization effects within the SFTs. The electronic behaviour of the SFTs can be described well by the particle-in-a-box model. Our findings demonstrate that controlled preparation of SFTs may offer an alternative way to achieve well-decoupled nanoparticles of high crystalline quality in metal thin films without the need of thin insulating layers.status: publishe