10min:

MIKHAIL A. STRZHEMECHNY, IRINA V. LEGCHENKOVA, ANATOLI I. PROKHVATILOV, YURI E. STETSENKO, KONSTANTIN A. YAGOTINTSEV, ANATOLI A. AVDEENKO, VICTOR V. EREMENKO, PYOTR V. ZINOVIEV, VICTOR N. ZORYANSKI, NATALIA B. SILAEVA, Verkin Institute for Low Temperature Physics and Engineering, 47 Lenin Ave., Kharkov 61103, Ukraine; AND RODNEY S. RUOFF, Northwestern University, Department of Mechanical Engineering, 2145 Sheridan Road, Evanston, Illinois 60208, USA.

Powder x-ray diffractometry was employed to study infusion of He into C₆₀ fullerite. It has been shown that the intercalation at a pressure of 1 Bar is a two-stage process, the first stage being the saturation of the octahedral voids, virtually complete after 55 hr. Photoluminescence spectra were taken at 5 K from C₆₀ with completely saturated octahedral voids. Helium in the lattice voids is shown to reduce that part of the luminescent emission which is due to 0-0 transitions around 1.69 eV from the so-called deep traps, or according to existing notions, the covalently bound pairs of C₆₀ molecules. The effect of He intercalation on polymeric dimer formation is ascribed to the changes in the pentagon to hexagon configuration ratio caused by the intercalation-related increase of the lattice parameter and the formation of bound states of He atoms in the C₆₀ lattice voids.