Anomalous Isotope Effects of Fulleride Superconductors

Abstract

The numerical calculations of the standard Eliashberg-Nambu strong coupling theory and a formula of isotope effect derived in this paper provide direct evidences that an-harmonic vibrations of lattice enhance isotope effect with anomalous coefficient α > 1/2. The results in this paper explain very well the wide distributed α values for the samples with different ratios of substitutions of 12 C by 13 C of fulleride superconductor Rb 3 C 60 . The calculations of isotope effects indicate that the intra-molecule radial modes have more important contributions to superconductivity than the intra-molecule tangential modes with higher phonon frequencies PACS: 74.20.Fg, 74.70.Wz, 71.20.Tx, 81.05.Tp

Propagation Mechanism of Cylindrical Cellular Detonation

“…[12,13] The variations of detonation wave structure and the pressure behind the wave at different initial temperatures were investigated by numerical simulations. [14] However, for cylindrical detonation, the instability of detonation displays an irregular cellular structure. At different detonation stabilities, the characteristics of cylindrical cellular detonation, the evolution of transverse waves along the front, the cell divergencce mechanism of cylindrical cellular detonation and the effect of instability on cylindrical cellular detonation remain unclear.…”