The thermal expansion of single-walled carbon nanotubes at low temperatures

• Дата: 2009
• Автор: Dolbin, A.V.
• Формат: Стаття
• Мова: English
• Опубліковано: НТК «Інститут монокристалів» НАН України 2009
• Назва видання: Functional Materials
• Теми: Characterization and properties
• Онлайн доступ: http://dspace.nbuv.gov.ua/handle/123456789/138932
• Назва журналу: Digital Library of Periodicals of National Academy of Sciences of Ukraine
• Цитувати: The thermal expansion of single-walled carbon nanotubes at low temperatures // A.V. Dolbin // Functional Materials. — 2009. — Т. 16, № 4. — С. 390-398. — Бібліогр.: 50 назв. — англ.

The radial thermal expansion coefficient αr of pure and Xe-saturated bundles of singlewalled carbon nanotubes has been measured in the interval 2.2-120 K. The coefficient is positive above T = 5.5 K and negative at lower temperatures. The sample was prepared by compacting a CNT powder such that the pressure applied oriented the nanotube axes perpendicular to the axis of the cylindrical sample. The data show that individual nanotubes have a negative thermal expansion coefficient while the solid compacted material has a positive one due to expansion of the intertube volume in the bundles. Doping the nanotubes with Xe caused a sharp increase in αr in the whole temperature range used, and a peak in the dependence αr(T) in the 50-65 K interval. A subsequent decrease in the Xe concentration lowered the peak considerably but had a little effect on the thermal expansion coefficient of the sample outside the peak region. The features revealed have been explained qualitatively.