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NANOSYSTEMS: PHYSICS, CHEMISTRY, MATHEMATICS, 2018, 9 (1), P. 38-40
Terrestrial development of the experiments on the fullerite C60 crystal
growth in microgravity
A. V. Bazhenov1, D.N. Borisenko1, E.B. Borisenko1, A. S. Senchenkov2, A. V. Egorov2, N.N. Kolesnikov1, A. A. Levchenko1
1Institute of Solid State Physics, Russian Academy of Sciences, Chernogolovka, Russia 2 Research and Development Institute for Launch Complexes, Moscow, Russia
bazhenov@issp.ac.ru, bdn@issp.ac.ru, borisenk@issp.ac.ru, 022@niisk.ru, nkolesn@issp.ac.ru, levch@issp.ac.ru PACS 81.10.h; 81.10.Bk DOI 10.17586/2220-8054-2018-9-1-38-40
Microgravity creates favorable conditions to reduce dislocations and grain boundaries density in growing crystals due to absence of close contact with the ampoule walls and absence of plastic deformation of the crystal under its own weight. For improvement of the fullerite C60 crystal growth technology before the scheduled space experiments on the ISS the growing of the high purity grade fullerite C60 crystals with the sufficiently high structural perfection were carried out on the Earth from the C60 vapor in sealed quartz ampoules (pre-evacuated to the pressure of 10-3 Pa) at temperatures in the evaporation zone ranging from 560 - 610 °C with a temperature gradient between the evaporation and deposition zones of 3 - 10 K/cm within 72 h. The grown single crystals had a size of ~ 5 X 5 X 5 mm and habitus corresponding to the fcc lattice. IR spectroscopy shows the high purity fullerite C60.
Keywords: fullerite, C60, crystal growth, sublimation, microgravity, IR spectroscopy.
Received: 16 June 2017 Revised: 17 October 2017
1. Introduction
To investigate the electron-electron correlation and polaron effects caused by the small conduction band (width of 0.05 eV) the perfect fullerite C6o crystals with sufficiently large overall dimensions (about several millimeters) are required. The continuous growth of fullerite C60 crystals by physical vapor transport has been described by the various authors [1-3]. The fullerite C60 crystals grown in the first experiments in microgravity aboard the FOTON-M3 spacecraft [4] had more perfect crystal structure in comparison with the crystals grown on the Earth: microgravity creates favorable conditions to reduce the dislocations density and grain boundaries in the growing crystals due to absence of close contact with the ampoule walls and absence of plastic deformation of the crystal under its own weight.
2. Experimental
For further improvement of the technology before the scheduled space experiments on the ISS, the growing of the high purity grade fullerite C60 crystals with the sufficiently high structural perfection were performed on the Earth from the C60 vapor in sealed quartz ampoules (pre-evacuated to the pressure of 10-3 Pa) at temperatures in the evaporation zone ranging from 560 - 610 °C with the temperature gradient between the evaporation and deposition zones of 3 - 10 K/cm within 72 h. The preparation of initial samples for analogous growth experiments was studied in detail in the previous work [5] and in our case, includes a low-temperature treatment of the fullerene C60 powder under dynamic vacuum of 10-3 Pa at the temperature of 350 - 400 °C within 3 h, then this powder was sublimated under dynamic vacuum of 10-3 Pa at 600 - 650 °C within 8 h. From this sublimated powder the primary fullerite C60 crystals were grown under a static vacuum of 10-3 Pa in sealed quartz ampoules at the temperature 610 °C with the temperature gradient between the evaporation and deposition zones 5 K/cm within 72 h. Then the regrowth of the primary deposit was run at the same conditions, yielding the high purity material. After these purification procedures, the resulting material was charged into quartz ampoules evacuated to a pressure of 10-3 Pa, hermetically sealed and placed into the multi-zone growth furnace for crystal growth. Three types of the gradients used in the experiments are shown in Fig. 1. The polycrystalline deposits of C60 were obtained in the runs #1 and #2. The fullerite C60 single crystal was grown in the run #3.
Terrestrial development of the experiments on the fullerite C60 crystal growth in microgravity
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500 J-t-,-T-,-T-,-T-r-
20 40 60 80
Length, mm
Fig. 1. Three types of the gradients of the multi-zone growth furnace (runs #1, #2, #3)
3. Results and discussion
The single crystals grown in the run #3 have the size of about 5 x 5 x 5 mm and habitus corresponding to the fcc phase of C60 (see Fig. 2). The presence of twins was revealed using the optical microscopy and the single-crystal diffractometer Oxford Diffraction Gemini-R. The twins interface corresponds to the {111} fcc conjunction plane.
Fig. 2. Optical image of the twins (arrows point "rungs" - the twins interface)
IR transmission spectrum of the C60 powder produced from the fullerite of run #3 is represented in Fig. 3. Strong scattering on shorter waves is explained by the KBr surface roughness. These data show the high purity of fullerite C60 after the overall technology chain.
4. Conclusions
The heating rate and the temperature distribution in the furnace must be carefully controlled because they have strong influence on the nucleation and growth rate and hence on the perfection of the grown crystals. Optimizing these parameters, the large C60 single crystals of good quality with size more than 5 mm can be grown reproducibly.
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A. V. Bazhenov, D. N. Borisenko, E. B. Borisenko, et al.
70 60
Wave number, cm"1
Fig. 3. IR spectrum measured for fullerite C60 single crystal from the run #3
References
[1] De Bruijn J., Dworki A., et al. Thermodynamic properties of a single crystal of fullerene 60: a DSC Study. Europhys. Lett., 1993, 24 (7), P. 551-557.
[2] Xiao Rong-Fu. Growth of large fullerene C60 crystals and highly oriented thin films by physical vapor transport. J. Cryst. Growth, 1997, 174, P. 821-827.
[3] Verheijen M.A., van Enckevort W.J.P., Meijer G. Growth phenomena on C60 crystals. Chem. Phys. Lett., 1993, 216 (1-2), P. 72-80.
[4] Bazhenov A. Fullerit C60 single crystal growth aboard the FOTON-M3 spacecraft. Proceedings of 60th Intern. Astronautical Congress, Daejeon, Republic of Korea 12-16 October 2009, P. 630-633.
[5] Sidorov N.S., Palnichenko A.V., et al. The method of the high purity grade fullerene C60 crystals production. Patent 2442847 Russia: MPK C30B 23/00, 2010119780/05, 20.02.2012, Bull. 5.
