Codoped Mg1-x(AlLi)xB2 compounds: a key system to probe the effect of charge doping and inter-band scattering

We prepared a series of Mg1−xAlLixB2 samples with 0x0.45 in order to compensate with Li theelectron doping induced by Al. Structural characterization by means of neutron and x-ray diffraction confirmsthat Li enters the MgB2 structure even though in an amount less than nominal one. We performed susceptibility,resistivity, and specific heat measurements. Vibrational properties were also investigated by means ofRaman spectroscopy. We compare these results with those obtained on a homologous series of Mg1−xAlxB2samples. The systematic success of scaling the relevant properties with the Al content rather than with theelectron doping suggests that lattice deformation plays an important role in tuning the superconductingproperties.