Izvestiya of Saratov University.
Physics
ISSN 1817-3020 (Print)
ISSN 2542-193X (Online)

nanostructures

EXACT SOLUTIONS OF THE ISING MODELS IN A MAGNETIC FIELD

Previously, the author solved the one-, two- and three-dimensional Ising models in the absence of an external magnetic field exactly. Additional convincing proofs for these solutions are given here. The exact solutions of the Ising models in a magnetic field are found. It is shown that the conventional methods of solving the Ising models are incorrect. Heat capacities and zero-field magnetic susceptibilities of the Ising models are calculated exactly for all dimensions (including the case of polonium) and a flaw in Onsager’s solution for heat capacity is detected.

Effect of Small Doses of Gamma Radiation on the Optical Properties of Nanostructured Silicon Obtained by Metal-Stimulated Chemical Etching in situ

Background and Objectives: Porous silicon nanowires (SiNP) obtained by the method of metal stimulated chemical etching (EE method) are of great interest. The physical properties of this material depend significantly on the morphology of the nanostructures and their sizes. Given in the literature data on the effect of small doses of ionizing radiation on metals and alloys and the effect of irradiation on the properties of porous silicon and SiNP, makes sense to modify not only the substrate, but also the SiNP layer during its formation by irradiation.

Nanostructured Porous Silicon Layers Formation at Low Doses of γ-Radiation

We present results of experimental study of nanoporous Si (SiNР) structure formation by using the method of metal-stimulated chemical etching upon irradiation with small doses of γ-radiation directly in the process of production (in situ). It is shown that the radiation leads to an increase of the crystallization of SiNP structures obtained on previously irradiated substrates. Apparently, this can be explained by a decrease in the initial defectiveness of the silicon substrate due to irradiation with small doses of γ-radiation.

Model of the Processes Nanostructure Formation during Plasma Spraying Hydroxyapatite Porous-Powder Coatings

We offer a physical model of the process nanostructure formation during plasma spraying hydroxyapatite coatings and described the thermodynamics of heating particle in the plasma torch. We analyzed thermal processes on the base and the formation of thermal fields in the system particle-base by plasma spraying. Possibly that the formation of amorphous coatings, consisting of submicron particles, happened because shear through by contact with the material and base and nanosized crystals appear as a result of very fast cooling (quenching) of the submicron structures.