Кафедра "Фізика"

Постійне посилання колекціїhttps://repository.kpi.kharkov.ua/handle/KhPI-Press/7578

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

Кафедра "Фізика" створена у 2016 році шляхом об'єднання кафедри "Загальна та експериментальна фізика" і кафедри "Теоретична та експериментальна фізика", заснованої в 1972 році. .

У 1885 р. для викладання в інституті курсу фізики на посаду ад’юнкт-професора був запрошений магістр фізики приват-доцент Харківського університету Олександр Костянтинович Погорілко. У різні роки на кафедрі працювали видатні вчені-фізики: Пільчиков Н. Д., Латишев Г. Д., Обреїмов І. В., Пінес Б. Я., Ландау Л. Д., Корсунський М. І., Веркин Б. І., Дмитренко І. М., Базакуца В. А., Кулик І. О., Янсон І. К., Басс Ф. Г. Гуревич Ю. Г., Косевич В. М., Кукушкін Л. С. та ін.

Кафедра входить до складу Навчально-наукового інституту комп'ютерного моделювання, прикладної фізики та математики Національного технічного університету "Харківський політехнічний інститут".

У складі науково-педагогічного колективу кафедри працюють: 2 доктора та 16 кандидатів фізико-математичних наук, 2 кандидата технічних наук, 1 кандидат педагогічних наук; 2 співробітника мають звання професора, 12 – доцента.

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2015 - 20187

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Автор: search.filters.author.Martynova, K. V.Містить файли: Так

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    Magnetoresistance of Polycrystalline Bi₁₋ₓSbₓ Alloys (x = 0 – 0.07)
    (IEEE, 2017) Doroshenko, A. N.; Martynova, K. V.; Rogacheva, E. I.
    A detailed investigation of the composition dependences of magnetoresistance for polycrystalline Bi₁₋ₓSbₓ solid solutions in a concentration range x = 0 – 0.07 was performed at 300 K in weak and strong magnetic field. It was shown that the composition dependences of magnetoresistance are clearly expressed nonmonotonic type. The presence of concentration anomalies of magnetoresistance was confirmed that had been earlier observed in the range x = 0 – 0.1 on cast samples after different kinds of thermal treatment and interpreted as a manifestation of electron phase transitions. It is shown that the position of the extrema does not depend on the magnitude of the magnetic field in the interval 0.01 - 1.0 T.
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    Microhardness of Sb₂Te₃ – Bi₂Te₃ Solid Solutions
    (2015) Martynova, K. V.; Rogacheva, E. I.
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    Thermoelectric properties of cold-pressed (Bi₁₋ₓSbₓ)₂Te₃ semiconductor solid solutions
    (FOP Panov A. M., 2017) Martynova, K. V.; Rogacheva, E. I.
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    Thermoelectric properties of polycrystalline Bi₁₋ₓSbₓ solid solutions in the concentration range x = 0 – 0.25
    (National Academy of Sciences of Ukraine, 2016) Doroshenko, A. N.; Rogacheva, E. I.; Drozdova, A. A.; Martynova, K. V.; Men'shov, Yu. V.
    A detailed investigation of the dependence of thermoelectric properties of polycrystalline Bi₁₋ₓSbₓ solid solutions on composition in a wide concentration range (x = 0 – 0.25) was performed at room temperature. The objects of study were cast samples of various composition obtained by ampoule method in one technological cycle consisting in cooling of ampoules with melts in the air and subsequent long homogenizing annealing at temperature (520 ± 5) K for 720 hours. It was shown that the composition dependences of properties are of clearly expressed nonmonotonic type. The presence of concentration anomalies of thermoelectric properties was confirmed that had been earlier observed in the range x = 0 – 0.1 on cast samples after different kinds of thermal treatment and interpreted as manifestation of electron phase transitions. A complicated nature of dependences at x > 0.1 is attributable to qualitative changes in Bi₁₋ₓSbₓ band structure at certain critical compositions, a change in relative contribution to conductivity of charge carriers from different energy bands with a change in antimony concentration and high sensitivity of energy spectrum and physical properties of Bi₁₋ₓSbₓ к to external effects.
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    Thermoelectric and mechanical properties of (Bi₁₋ₓSbₓ )₂Te₃(x = 0÷0.07) semiconductor solid solutions
    (National Academy of Sciences of Ukraine, 2016) Rogacheva, E. I.; Martynova, K. V.; Bondarenko, A. S.
    The dependences of thermoelectric properties and microhardness on the composition of polycrystalline (Bi₁₋ₓSbₓ )₂Te₃ solid solutions in the concentration range x = 0÷0.07 at room temperature were investigated. A drastic growth of microhardness was discovered with a simultaneous reduction of the Hall coefficient, the Seebeck coefficient and electric conductivity with increase in antimony content x = 0.005 – 0.01, following which with further increase in x to x = 0.01 – 0.015, the type of the dependences was reversed. The observed effect is attributable to a high degree of crystal lattice disorder with the introduction of the first portions of impurity and to subsequent relaxation processes with formation of percolation channels in crystal impurity subsystem. With further increase in x, the Hall coefficient and the Seebeck coefficient practically do not change with composition, and the observed more complicated dependence of microhardness and electric conductivity on x is interpreted as a manifestation of short-range processes in a solid solution.
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    Документ
    Thermoelectric properties of cold pressed samples of semiconductor (Bi₁₋ₓSbₓ)₂Te₃ solid solutions
    (Науково-технологічний комплекс "Інститут монокристалів", 2018) Martynova, K. V.; Rogacheva, E. I.
    The composition dependences of thermoelectric (TE) properties of (Bi₁₋ₓSbₓ)₂Te₃ solid solutions (0 < x < 1) produced by cold pressing and subsequent annealing were investigated at room temperature. Samples were prepared from cast polycrystals, obtained by the cooling of melt down to room temperature in evacuated quartz ampoules and subsequent annealing. It was established that cast samples exhibited p-type conductivity in the entire composition range, and an increase in the Sb₂Te₃ content led to the growth of electrical conductivity and drop of the Seebeck coefficient. The change of the conductivity type from positive to negative in the composition range x = 0 - 0.6 took place after cold pressing and composition dependencies of the properties became more complex. The maximum figure of merit value (Zmax = (3.1±0.4)·10⁻³ K⁻¹) that was achieved in cold-pressed annealed samples at x = 0.8 was comparable to the values of Z for single crystals of undoped (Bi₁₋ₓSbₓ)₂Te₃ solid solutions and for polycrystalline samples produced by other methods. It follows from the data obtained that the proposed method of preparing the samples of (Bi₁₋ₓSbₓ)₂Te₃ solid solutions by cold pressing and subsequent annealing may appear to be useful in thermoelectric devices.