Influence of Rb, Cs and Ba on superconductivity of magnesium diboride
A. V. Palnichenko, O. M. Vyaselev, N. S. Sidorov
Institute of Solid State Physics, 142432 Chernogolovka, Moscow district., Russia
PACS: 74.25.-q, 74.62.Bf, 74.70.-b
Abstract
Magnesium diboride has been thermally treated in the presence of
Rb, Cs, and Ba. Magnetic susceptibility shows possible onsets of
superconductivity in the resulting samples at 52 K (Rb), 58 K (Cs) and 45 K
(Ba). Room-temperature 11B NMR indicates to cubic symmetry of the
electric field gradient at boron site for the samples reacted with Rb and Cs,
in contrast to the axial symmetry in the initial MgB2 and in the sample
treated with Ba.