Search

A study is performed of different conditions of the synthesis and growth of perfect crystals of the family of Mott insulators for creating memristors (new-generation memory elements). The ceramic synthesis of GaNb4Se8 compound is used in combination with the thermolysis of niobium selenides under nonequilibrium conditions, allowing a material with a high level of chemical uniformity to be created.

Transitions in the resistive switching of diode heterostructures based on bismuth selenide, in which bipolar resistive switching is implemented, are investigated. It is found that the time of transitions from one metastable state to another has a fast component on the order of microseconds and a slow component (a shuttle tail). Results are described using the model of a critical electric field, and the parameters of the investigated structures are calculated numerically.

Reversible and reliable bistable resistive switchings are observed in planar-type Nd2–xCexCuO4–y/Nd2–xCexO1.75/Ag junctions based on the Nd2–xCexCuO4–y superconducting films. Investigation of electronic structure of surface of the Nd0.5Ce0.5O1.75/Nd2–xCexCuO4–y via high-resolution X-ray photoelectron spectroscopy and atomic force microscopy (AFM) show that the key factor for the switchings is the presence of an oxygen-deficient Nd2-xCexO1.75 phase, epitaxially intergrown on surfaces of Nd2–xCexCuO4–y.

The bipolar effects of resistive switching (BRS) in mesoscopic heterostrucures based on amorphous and crystalline niobium oxide films are considered. The BRS effect is more pronounced in the structures based on multiphase nanocrystalline niobium oxide films. It is shown that the threshold frequency for observing the BRS effect is of the order of 104 Hz. Switching is controlled via oxygen electrodiffusion to vacancies as the doping level of the contact area and the resistive properties of the heterocontact change.

The effect applied voltage frequency has on bipolar resistive switching in microcontact type heterostructures based on thin films and single crystals of bismuth selenide is studied both experimentally and via numerical simulation.

Numerical simulation is used to study the effect anisotropic electrical conductivity and anisotropic oxygen diffusion have on the bipolar resistive switching effect in oxide compounds.

Thin-film heterojunctions Nd2 − x Ce x CuO4 − y /Ag were obtained. The bipolar effect of resistive switching in these heterostructures was detected and investigated. X-ray diffraction data indicate the presence of a second phase in thin films; along with the basic phase Nd2 − x Ce x CuO4 − y , it affects the behavior of the interface of investigated heterojunctions and leads to an alteration of the type of conductivity. The threshold frequency of alternating voltage at which the resistive switching effect is observed in heterojunctions was detected.

Simulations are used to study the influence of nonuniform electric field distribution at a heterojunction interface on the effect of bipolar resistive switching in oxide compounds. Computer models show that a conducting channel forms at the edge of a heterojunction area characterized by strong local increase in the electric field intensity. The computations are confirmed by the low temperature properties of metastable phases in heterojunctions based on high temperature superconductors.

It is shown that resistive switchings in heterocontacts formed by a doped manganite single crystal and a normal metal lead to the formation of a phase separated state in the manganite surface layer; the resistive and magnetic properties of this state can be significantly varied by changing the resistive switching parameters.