Neutron irradiation effects on two gaps in MgB2

In this paper, an overview of the gaps behaviour as a function of disorder in neutron-irradiated samples is presented. The general effects of neutron irradiation is discussed and, by comparing the different experiments performed in literature, we show that this technique is very effective to introduce disorder in a controlled way in MgB2. Then, the three experiments that allowed determining the two gaps, i.e. specific heat, point contact spectroscopy and scanning tunnelling spectroscopy measurements are analysed and compared, and the role of interband scattering is discussed. (c) 2007 Published by Elsevier B.V.