Low temperature microhardness of Xe-intercalated fullerite C60

• The Vickers microhardness of Xe-intercalated polycrystalline fullerite C60 (XexC60, x~=0.35) is measured in a moderately low temperature range of 77 to 300 K. A high increase in the microhardness of the material (by a factor of 2 to 3) as compared to that of pure C60 single crystals is observed. It is shown that the step-like anomaly in the temperature dependences of the microhardness of pure C60 single crystals recorded under the orientational fcc-sc phase transition (Tc~=260 K) is also qualitatively retained for XexC60, but its onset is shifted by 40 K towards lower temperatures and the step becomes less distinct and more smeared. This behavior of H-barV(T) correlates with x-ray diffraction data, the analysis of which revealed a considerable influence of xenon interstitial atoms on the peculiar features of fullerite thermal expansion due to orientational phase transitions (see the paper by A.I. Prokhvatilov et al. in this issue).

Subject headings

NATURVETENSKAP  -- Fysik -- Den kondenserade materiens fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Condensed Matter Physics (hsv//eng)

Keyword

Fullerenes

C60

polyamorphism

hardness

orientational glass

Xenon

Xe

XRD

intercalation

transition temperature

structure

Condensed matter physics

Kondenserade materiens fysik

Publication and Content Type

ref (subject category)

art (subject category)