Ion-induced formation of micropolycrystalline Nb1-xCx (0 ≤ x < 0.3) thick coatings with quasi-ternary phase structure

• Дата: 2001
• Автори: Sleptsov, S.N., Sleptsov, A.N.
• Формат: Стаття
• Мова: English
• Опубліковано: Національний науковий центр «Харківський фізико-технічний інститут» НАН України 2001
• Назва видання: Вопросы атомной науки и техники
• Теми: Физика радиационных повреждений и явлений в твердых телах
• Онлайн доступ: http://dspace.nbuv.gov.ua/handle/123456789/78272
• Назва журналу: Digital Library of Periodicals of National Academy of Sciences of Ukraine
• Цитувати: Ion-induced formation of micropolycrystalline Nb1-xCx (0 ≤ x < 0.3) thick coatings with quasi-ternary phase structure / S.N. Sleptsov, A.N. Sleptsov // Вопросы атомной науки и техники. — 2001. — № 4. — С. 39-45. — Бібліогр.: 52 назв. — англ.

Structure and superconductivity of thick polycrystalline niobium-carbon coatings (Nb1-xCx, 0 ≤ x < 0.3) deposited from low-energy self-ion-atomic Nb- and C- fluxes onto substrates with the temperature range 500…650 K were studied by X-ray diffraction (XRD) analysis, transmission electron microscopy (TEM), electron diffraction, TEM of oxidic replicas and resistivity measurement method at low temperature. It is founded, that Nb1-xCx coatings with carbon concentration range 9…15 at.% have an unusual high superconducting transition temperature Tc ≈ 12 K. Dependency of critical current density of these coatings on temperature is not monotonous and have a sharp bend near TC ≈ 9.5 K Structural analysis of these coatings has revealed they have a quasi-ternary phase composition consisting of Nb(b.c.c.), subcarbide Nb₂C(c.p.h.) and metastable carbide 'NbCx' with f.c.c. structure. The results obtained are discussed from a point of view of 'NbCx' phase forming at Nb and Nb₂C phases interface. It is also shown, that Nb1-xCx coatings with carbon concentration less than 5 at.% revealed supersaturated solid solution and have TC ≈ 9.5 K. Kinetics of diffusive decomposition of niobium-carbon coatings during isothermal annealing was also investigated.