Предложен метод определения аппаратной функции при измерениях поверхностного потенциала в режиме Кельвин-зонд-микроскопии. Метод основан на применении в качестве тестовой структуры поверхности политипов SiC, содержащих области однослойного и двухслойного графена. Измерение профилей потенциала вдоль различных направлений на такой поверхности позволяет определить аппаратную функцию для зондовых измерений потенциала. Используя аппаратную функцию, можно выполнять процедуру деконволюции и восстанавливать точный потенциал поверхности. Ключевые слова: сканирующая зондовая микроскопия, Кельвин-зонд-микроскопия, потенциал поверхности, тестовые структуры, графен, карбид кремния.

Abstract SPM studies of triboelectric charges on thin films of high-k dielectrics LaScO3, semiconductor ”flakes“ MoSe2, and ferroelectric PZT films have been carried out. It is shown that the value of the accumulated triboelectric charge in these films depends on their thickness. The strongest effect is observed in the LaScO3 film 6 nm thick and the PZT film 100 nm thick. The dependence of the value of the measured triboelectric potential on the loading force and the material of the probe was also experimentally found.

The elastic deformations in the conical nanowires are considered. An analytical expression was obtained for the distribution of elastic deformations along the length of the conical nanowire. It was found that at certain cone angles in nanowire there is an extended area of sufficiently high deformations comparable or even large than the deformation at the base of the nanowire.

The results of ab initio calculations of the spin-polarized band structure of graphene on silicon carbide intercalated with cobalt and silicon atoms are presented. It is shown that metal and silicon atoms during intercalation are localized between the substrate and the buffer layer of carbon atoms. Initially, the cobalt layer is strongly coupled with the buffer layer. The subsequent intercalation of silicon and the formation of cobalt silicide leads to a transition from hybridized state to the formation of quasi-freestanding bilayer graphene on the surface of the system due to the transformation of the buffer layer to the second graphene layer.

The ab initio calculations have been performed for the spin-polarized band structure of graphene on silicon carbide intercalated with cobalt and silicon atoms. The cobalt and silicon atoms are shown to be localized during intercalation between the substrate and buffer layer of carbon atoms. The subsequent silicon intercalation and the formation of cobalt silicide lead to the transition from a strong hybridization to the formation of a quasi-free two-layer graphene on the system surface due to the transformation of the buffer layer to the second graphene layer.

The local polarization processes in thin BaTi1-xZrxO3 films were investigated by contact conducting scanning probe microscopy and piezoresponse microscopy. A relationship between the direction of the created domains and the magnitude of the flowing currents is established. The value of the residual polarization is found, and the hysteresis loop is measured using scanning probe microscopy as well as the values ​​of the piezomodule dzz and the value of the coercive field Ec for these films are determined.

В рамках теории функционала спиновой плотности (SDFT) впервые представлены теоретические результаты компьютерного моделирования магнитных свойств ультратонких пленок железа на немагнитной подложке из гексагонального нитрида бора Gr/Fe/h-BN. Основное внимание уделено численным исследованиям магнитной анизотропия пленок железа c гексагональной структурой, аналогичной кристаллической структуре интеркалированных пленок железа в системе Gr/Fe/Ni (111). Для этого рассчитаны полные энергии ферромагнитных структур с различными направлениями магнитных моментов атомов железа относительно поверхности пленки. Проанализировано влияние графена на магнитные свойства системы Gr/Fe/h-BN. Результаты теоретического моделирования Fe/h-BN и Gr/Fe/h-BN показывают, что в такой системе можно получить достаточно "толстые" пленки (dFe≥10 Angstrem) железа, которые будут обладать перпендикулярной магнитной анизотропией. Ключевые слова: тонкие магнитные пленки, функционал спиновой плотности, магнитное диполь-дипольное взаимодействие, магнитная кристаллографическая анизотропия.

Local polarization processes in BaTi 1 – x Zr x O 3 thin films are studied using contact conductive scanning probe microscopy and piezoelectric response microscopy. The relationship between the direction of the created domains and the magnitude of the flowing currents is established. The value of the residual polarization is found. Using scanning probe microscopy, the hysteresis loop is measured and the values of the piezoelectric modulus d zz and coercive field E c for these films are determined.

The ab initio calculations of the magnetic anisotropy of thin (to six monolayers) nickel films and iron films with unusual fcc structures formed upon intercalation of graphene with Fe atoms are presented. The data have been obtained for both the pure-surface films and the films coated with graphene. The density functional theory and the pseudopotential method are used to calculate the magnetic moments of atoms of all the layers and to determine the total energies of the structures with different orientations of magnetic moments of iron and nickel atoms with respect to the film surface. A strong influence of graphene on the magnetic properties contacting iron films is demonstrated.

The time dynamics of the spatial distribution of electrons locally injected from the probe of an atomic force microscope into thin (less than 10 nm) ZrO2(Y) films with embedded Au nanoparticles on Si substrates is studied via Kelvin probe force microscopy. The profiles of the film surface potential induced by the injection of a countable number (several tens) of electrons into Au nanoparticles, as a function of the time elapsed after injection, are measured and analyzed.

AbstractThe ab initio calculations of the magnetic anisotropy of thin (to six monolayers) nickel films and iron films with unusual fcc structures formed upon intercalation of graphene with Fe atoms are presented. The data have been obtained for both the pure-surface films and the films coated with graphene. The density functional theory and the pseudopotential method are used to calculate the magnetic moments of atoms of all the layers and to determine the total energies of the structures with different orientations of magnetic moments of iron and nickel atoms with respect to the film surface. A strong influence of graphene on the magnetic properties contacting iron films is demonstrated.

In the present study the evolution of the electronic structure of the graphene/Fe/Ni(111) interface with increasing number of intercalated iron atoms is investigated. The Eσ(k) dependences and full and partial densities of states are calculated within density functional theory. It is shown that an increase in the number of iron layers does not affect the electronic structure, but greatly affects the magnetic properties of the interface.

Исследование нанокристаллов CsPbBr 3 и их агломератов с помощью методов комбинированной сканирующей зондовой микроскопии и оптической спектрометрии

AbstractThe electrical properties of GaAs nanowires grown on a 6 H -SiC (0001) substrate covered with graphene single layers and bilayers are studied. The nanowires are grown by molecular-beam epitaxy, with gold as a catalyst. The electrical properties are studied by measuring and analyzing the current–voltage characteristics of single nanowires vertically grown on a substrate. Numerical simulation of the experimental current–voltage curves revealed the presence of a ~0.6-V-high Schottky barrier between the nanowires and graphene. The appearance of the barrier is due to the formation of excess arsenic at the nanowire/graphene interface.

We report on the investigation results of electric properties of amorphous hydrogenated carbon with nickel nanoparticles, a-C : H(Ni) on glassceramic substrates. The films are synthesized by reactive ion-plasma magnetron sputtering. The analysis results of the effect of nickel (Ni) concentration in dc conductivity σ and the values of complex permittivity ε* in the frequency range 8–12 GHz are considered. The real part ε' of the complex permittivity of samples reaches 100, while the imaginary part ε'' attains 212. The nickel concentration in the films corresponding to the percolation threshold amounts to 22–25 at %.

AbstractA method of local anodic oxidation has been used to obtain graphene-oxide regions on SiC. The change of the surface properties was confirmed by atomic-force microscopy and Raman spectroscopy. Experimental data were obtained on the conductivity, potential, and topography of the oxidized regions. It was shown that the oxidation leads to a rise in the surface potential. A relationship was found between oxidation parameters, such as the scanning velocity and the probe voltage. The method of local anodic oxidation was used to obtain by lithography an ~20-nm-wide nanoribbon and an ~10-nm-wide nanoconstriction.