Purpose of the development: Designed to obtain a semiconductor material with ferromagnetic properties at room temperature.

Recommended application field: Technology for producing ferromagnetic semiconductor materials can be used in semiconductor spintronic and instrumentation, as well as objects of study of the physical phenomena and the interaction of semiconductor and magnetic systems.

Advantages over analogues: There are ways to get interkalyatnyh semiconductor materials, which allows implementation in layered different elements. But here there is a restriction on the parameters of modes of electrochemical intercalation process in the iron group, due to their low potential selection (narrows the regulatory process capabilities that interfere with surface metallization, the occurrence of hydrated complexes). In addition, there are no data on the effect of magnetic field on the process of intercalation and ferromagnetic properties of semiconductor crystals GaSe, intercalated in the iron group. The proposed method allows to obtain a ferromagnetic semiconductor material based on GaSe, uniformly intercalated by volume, combining semiconductor properties with high magnetic characteristics. Using the proposed method provides a laminated semiconductor crystals 0,15 GaSe (x - number of embedded Co atoms per formula unit GaSe) with strong ferromagnetic properties. This is explained by the fact that for the intercalate Co 0,15 GaSe, received introduction of the magnetic field dependence of the magnetic moment of the magnetic field, measured along and across the layers intercalate Co 0,15 GaSe, the form of the hysteresis loop, as opposed to intercalate Co 0,15 GaSe, obtained without a magnetic field, for which such a dependence is not observed.

The development stage readiness: Pre-production model is made

Description of the development:
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A method of producing a ferromagnetic semiconductor material is based on the method of implementation of the electrochemical (intercalation) of cobalt ions in the interlayer space of single crystals of layered semiconductor GaSe. The implementation process of the cobalt ions occurs in samples that are in a constant magnetic field directed perpendicular to the direction of the electric current. The process of obtaining a semiconductor material according to the invention, begins with the manufacture and selection of the initial samples GaSe. GaSe single crystals were grown by the Bridgman method from the melt of the stoichiometric composition. At room temperature, the samples had a p-type conductivity with a carrier concentration p = 10 [13] - 10 [14] cm-3 and mobility of m = 25 - 30 cm 2 / V * s. Weissenberg method established that the resulting crystal structure of e-GaSe (space group D1/3h). The width of the van der Waals gap GaSe is ~ 3.755 A, while the ionic radius of cobalt (Co) rCo = 0,82 A, which allows for efficient intercalation GaSe samples without destroying them. Electrochemical intercalation of cobalt was carried out by the "pull" of the electric field. Used as an electrolyte saturated aqueous CoSO4. Samples used for the intercalation of GaSe, size 10x5x1 mm. Since the d-elements have a low potential for selection, implementation was carried out in galvanostatic mode currents, the density of which does not exceed 0.4 mA/cm2, with no observed precipitation carried impurities or salt on the samples and the electrodes of the electrochemical cell. Under the influence of an external dc electric field was due to the introduction of the Co ions in the interlayer space of the crystal GaSe. Modes intercalation asked the current density j, the degree of intercalation (intercalant concentration) was determined by the product of jt. For intercalation used samples cleaved with one washer, the influence of concentration on the properties of cobalt implanted GaSe Identify on the same group of samples by dointerkalyatsii. The introduction took place in a closed electrochemical cell type Yasa-2 without a protective atmosphere at room temperature (T = 293 K). The magnetic characteristics of the intercalate Co0, 15GaSe measured by vibrating sample magnetometer magnetometer "Vibrating Magnetometer 7404 VSM" in magnetic fields up to 3000 Oe without protective atmosphere at room temperature (T = 293 K).

Information about newness of the development:
there are Ukrainian patents -- 1 items

Possibility of transfer abroad:
Licence's sale
Technological document's sale
Combinated reduction to industrial level
Joint production, sale, exploitation

Photo

Country Ukraine

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E-mail: gal@uintei.kiev.ua