Кафедра "Менеджмент"

Постійне посилання колекціїhttps://repository.kpi.kharkov.ua/handle/KhPI-Press/7475

Офіційний сайт кафедри http://web.kpi.kharkov.ua/mto

Від грудня 2021 року кафедра має назву "Менеджмент", попередня назва – "Менеджмент та оподаткування".

Кафедра "Менеджмент та оподаткування" заснована у 1991 році, добре відомим в Україні організатором науки та освіти, доктором технічних наук, заслуженим діячем науки і техніки України, академіком Леонідом Миколайовичем Івіним та є першою в Україні кафедрою менеджменту.

Кафедра входить до складу Навчально-наукового інституту економіки, менеджменту і міжнародного бізнесу Національного технічного університету "Харківський політехнічний інститут". За понад 30-річний період кафедрою здійснено підготовку і випуск понад 2000 фахівців в області менеджменту.

У складі науково-педагогічного колективу кафедри працюють: 3 доктора економічних наук, 23 кандидата наук: 18 –економічних, 2 – технічних, 1 – фізико-математичних, 1 – педагогічних, 1 – наук з державного управління; 2 співробітника мають звання професора, 18 – доцента. Викладачі кафедри мають практичний міжнародний досвід та володіють англійською мовою, що дає змогу проводити навчання як українською, так і англійською мовами.

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Concentration dependences of galvanomagnetic and thermoelectric properties of Bi1-xSbx thin films in the range x = 0 – 0.25
(Національна академія наук України, 2019) Rogacheva, E. I.; Doroshenko, A. N.; Sipatov, A. Yu.; Nashchekina, O. N.
Effect of Deviation from Stoichiometry on Thermoelectric Properties of Bi₂Te₃ Polycrystals and Thin Films in the Temperature Range 77-300 K
(Сумський державний університет, 2019) Rogacheva, E. I.; Novak, K. V.; Doroshenko, A. N.; Nashchekina, O. N.; Budnik, A. V.
Bi₂Te₃ semiconductor compound and Bi₂Te₃-based solid solutions are presently among the best lowtemperature thermoelectric materials. One of the methods of controlling the conductivity type and properties of Bi₂Te₃ is changing the stoichiometry of this compound. Earlier, we have obtained the room-temperature dependences of mechanical and thermoelectric properties of Bi₂Te₃ polycrystals on the degree of deviation from stoichiometry. The goal of this work is to investigate the behavior of such dependences at other temperatures. Bismuth telluride polycrystals with compositions in the range of 59.6-67.5 at. % Te were obtained, and for all the crystals the Seebeck coefficient, the Hall coefficient, electrical conductivity and charge carrier mobility were measured in the temperature range 77-300 K. On the basis of the temperature dependences, the isotherms of kinetic coefficients were plotted. It was found that similar to the room-temperature isotherms, the isotherms at lower temperatures were non-monotonic: they exhibited inversion of the conductivity sign between 60.5 and 61.0 at. % Te and extrema near 60.0 and 63.0 at. % Te. The experimental data are interpreted taking into account changes in the band and defect structures of Bi₂Te₃ under varying stoichiometry. The obtained results make it possible to control thermoelectric properties of Bi₂Te₃ polycrystals in the temperature range 77-300 K by changing the degree of deviation from stoichiometry.
Electronic phase transitions in thin films of Bi1-xSbx solid solutions
(Grupo Pacifico, 2018) Rogacheva, E. I.; Doroshenko, A. N.; Nashchekina, O. N.
Galvanomagnetic properties of polycrystalline Bi₁₋ₓSbₓ solid solutions in the concentration range x = 0-0.25
(Науково-технологічний комплекс "Інститут монокристалів", 2020) Rogacheva, E. I.; Doroshenko, A. N.; Drozdova, A. A.; Nashchekina, O. N.; Men'shov, Yu. V.
The dependences of the Hall coefficient, electrical conductivity, magnetoresistance, electron and hole concentration and mobility on the Bi₁₋ₓSbₓ solid solution composition in the concentration range x = 0-0.25 at 77 and 300 K in magnetic fields 1 T and 0.05 T were obtained. It was shown that all the dependences exhibit a distinct nonmonotonic oscillating behavior at both temperatures and in both magnetic fields. The presence of concentration-dependent anomalies of galvanomagnetic properties is attributed to critical phenomena accompanying the percolation-type transition from dilute to concentrated solid solutions and electronic phase transitions: a transition to a gapless state, the semimetal – semiconductor transition, and indirect – direct band gap semiconductor transition.
Influence of Composition on the Thermoelectric Properties of Bi1-xSbx Thin Films
(IOP Publishing Ltd, 2016) Rogacheva, E. I.; Nashchekina, O. N.; Doroshenko, A. N.; Sipatov, A. Yu.; Dresselhaus, M. S.
Percolation effects and self-organization processes in Bi₂(Te₁₋ₓSeₓ)₃ solid solutions
(Easy Conferences Ltd, 2019) Rogacheva, E. I.; Shelest, T. N.; Martynova, E. V.; Doroshenko, A. N.; Nashchekina, O. N.
Percolation effects and self-organization processes in Bi₂(Te₁₋ₓSeₓ)₃ solid solutions
(Науково-технологічний комплекс "Інститут монокристалів", 2019) Rogacheva, E. I.; Shelest, T. N.; Martynova, E. V.; Doroshenko, A. N.; Nashchekina, O. N.; Men'shov, Yu. V.
The room-temperature dependences of microhardness H, electrical conductivity σ, the Seebeck coefficient S, and thermoelectric power factor P on composition of Bi₂(Te₁₋ₓSeₓ)₃ solid solutions were measured in the concentration range x = 0 - 0.07. In the intervals x = 0.0075 - 0.0175 and x = 0.025 - 0.035, an anomalous decrease in H and S and increase in σ with increasing x were observed. The first concentration-dependent anomaly was attributed to critical phenomena, accompanying a percolation-type phase transition. The percolation threshold xc and the radius of deformation spheres R₀ around Se impurity atoms were estimated. The second anomaly is assumed to be connected with a short-range ordering in the solid solution. The non-monotonic character of the dependences of H on the load on an indenter, whose behavior depended on the impurity concentration, was attributed to the interaction of the deformation fields created by dislocations and impurity atoms.
Percolation effects and self-organization processes in cold-pressed Bi2(Te1−xSex)3 solid solutions
(Elsevier Ltd, 2021) Rogacheva, E. I.; Martynova, E. V.; Shelest, T. N.; Doroshenko, A. N.; Nashchekina, O. N.
It was established that the dependences of thermoelectric and mechanical properties of cold-pressed Bi2(Te1−xSex)3 alloys on composition (x = 0–0.07) exhibit a non-monotonic behavior in certain concentration ranges: an anomalous decrease in the Seebeck coefficient, thermoelectric power factor, and microhardness, and increase in electrical conductivity with increasing x. We observed similar anomalies earlier for cast Bi2(Te1−xSex)3 alloys and explained them by percolation and self-organization phenomena. Thus, the existence of the anomalies does not depend on the method of sample preparation. However, in pressed samples as compared to cast ones conductivity type changes from p to n and thermoelectric power factor increases.
Temperature and concentration dependences of specific heat of Bi₁₋ₓSbₓ solid solutions
(Науково-технологічний комплекс "Інститут монокристалів", 2018) Rogacheva, E. I.; Doroshenko, A. N.; Nashchekina, O. N.
For Bi₁₋ₓSbₓ solid solutions, the concentration (x = 0 - 0.12) and temperature (170-525 K) dependences of specific heat Cp were obtained. At all temperatures studied, three peaks of Cp were observed near x = 0.015, x = 0.037, and x = 0.07. The observed effects were attributed to critical phenomena accompanying the second-order phase transitions: percolation transition from dilute to concentrated solid solutions, the transition to a gapless state, and the semimetal-semiconductor transition, respectively. It was shown that the values of critical indexes (α = 0.11 ± 0.01) are the same not only for different peaks but also for different temperatures and correspond to the values theoretically calculated within the framework of scale-invariant theory for three-dimensional (3D) models.
Temperature and magnetic field dependences of thermoelectric properties of Bi1-xSbx solid solutions in the range x = 0 – 0.25
(Easy Conferences Ltd, 2019) Rogacheva, E. I.; Doroshenko, A. N.; Nashchekina, O. N.
Temperature and magnetic field dependences of thermoelectric properties of Bi1-xSbx solid solutions in the range x = 0-0.25
(Elsevier Ltd, 2021) Rogacheva, E. I.; Doroshenko, A. N.; Nashchekina, O. N.
Bi1–xSbx solid solutions are the best n-type thermoelectric materials for use at temperatures ≤200 K. An important parameter determining material’s figure of merit is charge carrier concentration. To determine it correctly, one should carry out measurements in a weak magnetic field. On the basis of the magnetic field dependences of the Hall coefficient and magnetoresistance, the dependences of the weak magnetic field boundary Bc on composition (x = 0–0.25) and temperature (T = 77–300 K) for polycrystalline Bi1–xSbx alloys were plotted. It was established that the Bc(x) dependences exhibit a non-monotonic behavior which is attributed to the existence of electronic phase transitions.
Transport properties of the bismuth telluride thin films with different stoichiometry in the temperature range 77-300 K
(Науково-технологічний комплекс "Інститут монокристалів", 2020) Rogacheva, E. I.; Novak, K. V.; Doroshenko, A. N.; Nashchekina, O. N.; Budnik, A. V.
The objects of the present study are thin films with thicknesses d = 45-620 nm prepared by thermal evaporation in vacuum from a single source, using undoped p- and n-type Bi₂Te₃ polycrystals with different stoichiometry (60.0 and 62.8 at. % Te, respectively) as a charge, and subsequent condensation on glass substrates at 500 K. The temperature dependences of the Hall coefficient Rн, electrical conductivity σ, and Hall charge carrier mobility μн of thin films were obtained in the range 77-300 K. It was found that the films had the same type of conductivity as the initial polycrystals in the entire temperature range studied and, like in the initial crystals, σ and μн decreased with increasing temperature. The exponents ν in the μн(T) dependences for the bulk polycrystals were larger than those for the films and increased with increasing d. In contrast to the p-type bulk polycrystals, Rн of the p-type films decreased under increasing temperature. In the n-type Bi₂Te₃, Rн decreased with temperature for both thin films and bulk crystals, however, the character of the Rн(T) dependences for the crystals and films differed. The decrease in Rн with temperature before the range of intrinsic conductivity in all thin films is attributed to the existence of donor and acceptor defect states.