On the superconductivity of the Li sub(x)RhB sub(y) compositions

We observed superconductivity (T sub(c) [Asymptotically = to] 2-3 K) in Li sub(x)RhB sub(y) intermetallics wherein x and y vary over a wide compositional range. The crystal structure consists of a cubic unit-cell (a [Asymptotically = to] 12.1 A) with a centrosymmetric space group, Pn3n. A weak but positive pressure-induced increase of T sub(c) was observed. The correlations between the composition and each of the following were observed: the unit-cell dimensions, T sub(c), Sommerfeld coefficient gamma , Debye temperature [straighttheta] sub(D), and critical fields H sub(c1) and H sub(c2). The thermal evolution of the electronic specific heat within the superconducting phase followed a quadratic-in-T behavior. In addition, a paramagnetic Meissner effect (PME) was manifested during a low-field-cooled magnetization cycle. The manifestation of the quadratic-in-T behavior as well as the PME feature will be discussed.