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Pressure-temperature diagram of C 60 fullerene: structures and properties of resulted phases

Pressure-temperature diagram of C 60 fullerene: structures and properties of resulted phases S. Buga WP2 methods of synthesis crystal and disordered structures, anisotropy, texture types of disorder analytical methods Summary. WP2. Production of magnetic pressure-polymerized C 60

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Pressure-temperature diagram of C 60 fullerene: structures and properties of resulted phases

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  1. Pressure-temperature diagram of C60 fullerene: structures and properties of resulted phases • S. Buga • WP2 • methods of synthesis • crystal and disordered structures, anisotropy, texture • types of disorder • analytical methods • Summary

  2. WP2. Production of magnetic pressure-polymerized C60 Deliverable No. 3 Map of the p-T-t conditions for producing C60-based magnetic carbon. Characterization of structure and defects appearing at certain conditions Delivery Date - 18 month. [2.1] B. Sundqvist., Adv. Phys.,48, 1 (1999). [2.7] T L Makarova, B Sundqvist, R Höhne, P Esquinazi, et. al., Nature413, 716 (2001). [2.8] R. A. Wood, M. H. Lewis, M. R. Lees, S. M. Bennington, M. G. Cain, and N. Kitamura, J. Phys. Condens. Matter 14 L385(2002). [2.9]. T. L. Makarova, B. Sundqvist, and Y. Kopelevich. Synth. Met. 137 1335 (2003).

  3. z-direction F up to 2000 tons x-y-direction  400 mm Quasi-hydrostatic or nonhydrostatic compression

  4. Approximate P-T phase diagram showing the boundaries between the three phases of molecular C60.

  5. "Reaction map" for C60, showing the structural phases obtained after short term treatment

  6. "Reaction map" for C60, showing the structural phases obtained after short term treatment

  7. Simplified version of the reaction map for C60 , showing under which conditions samples with reported ferromagnetic properties have been produced. Square - Ref. [1], triangles - Refs. [2], ring - TL Makarova (unpublished), filled dot - Ref [3]. 1. Wood RA, Lewis MH, Lees MR, Bennington SM, Cain MG, Kitamura N J, Phys Condens Matter (2002) 14:L385 2. T L Makarova, B Sundqvist, R Höhne, P Esquinazi, et. al., Nature413, 716 (2001), Narozhnyi VN, Müller K-H, Eckert D, Teresiak A, Dunsch L, Davydov VA, Kashevarova LS, Rakhmanina AV, Synth Met. 3. Murakami T, Suematsu H., Pure Appl Chem (1996) 68:1463

  8. H. Sjostrom, et al., Superhard and elastic carbon nitride thin film having fullerenelike microstructure. PRL, 75 (1995) 1336 Hardness ~ 40 GPa (diamond 100-150 GPa, hard carbides, nitrides ~ 15-30 GPa )

  9. T.L. Makarova et al. Conductivity of two-dimensional C60 polymers, Carbon, 2001 Rh T 6 GPa, Rh phase z-direction x-y-direction Anisotropy ratio z /x y

  10. 6 GPa 2.5GPa

  11. S.G. Buga et al., Semimetallic and semiconductor properties of some superhard and ultrahard fullerites in th range 300-2 K. J. Phys & Chem. Sol., 2000 XRD patterns

  12. Magnetoresistance studies Hv~ 60-100 GPa

  13. S.G. Buga et al., Diam. & Rel. Mat., 2005 Sample No.8 : C60, 9.5 GPa, 950K

  14. V. Blank, Ye. V. Tatyanin and B.A. Kulnitskiy. Phys. Lett, 1996 Disordered 3D-polymeric crystal states Electron diffraction patterns and dark field micrographs taken from different arc reflections (a,b). The tilting angle between (c) and (d) is 60o.

  15. Science, 1999 z-direction x-y-direction

  16. SUMMARY • Various crystalline and disordered, textured structures can be obtained by HPHT treatment of C60 fullerene • The resulted structure depends strongly not only P&T values, • but the action path and time also • X-ray and TEM (SEM) analysis are efficient tools for structure characterisation • Electrical properties (conductivity, magnetoresistance), their anisotropy are very sensitive and indicative the structure and disorder Let’s go !

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