2Kurnakov Institute of General and Inorganic Chemistry of the Russian Academy of Sciences, 119991 Moscow, Russia pos Анотація:
Received Octouber 3, 2012
The superconducting properties of first synthesized new heterofullerides AnMmHgxC60 (A = K, Rb, Cs;
M = Be, Mg, B, Al, Ga, In; n = 1, 2; m = 1, 2; x<<1)
were investigated at low temperatures. The low frequency inductive method was used to detect a superconducting transition. All the samples were studied by using x-ray, solid state nuclear magnetic resonance, electron spin resonance, and Raman scattering. It is found that the maximum number of the superconducting heterofullerides are heterofullerides of potassium. The fulleride K2GaC60 has a critical temperature of the superconducting tarnsition Тс = 20 К. Heterofullerides of indium and borum are not superconductors. The synthesis of heterofullerides via amalgams (Hg–
K–Mg, Hg–Rb–Al) gives rise to two different superconducting phases.
PACS: 61.48.+c Structure of fullerenes and related hollow and planar molecular structures; PACS: 71.30.+h Metal-insulator transitions and other electronic transitions; PACS: 74.10.+v Occurrence, potential candidates.
Key words: superconductivity, fullerides, nuclear magnetic resonance, paramagnetic resonance, Raman scattering.