Neutron irradiation effects on anisotropic transport in Ca2-xSrxRuO4(x=0.2, 0.5)

In-plane ρa(T) and out-of-plane ρc(T) resistivities in magnetic fields H up to 14T were studied in single crystals Ca2-xSrxRuO4 (x=0.2,0.5) disordered by fast neutron irradiation (fluence 7.5x1018cm-2). Disordering leads to the development of low-temperature negative resistivity slope dρa(T)/dT<0, dρc(T)/dT<0. Such a behavior, together with the observed low-temperature magnetoresistance dρa(T)/dH<0, dρc(T)/dH>0, is discussed in terms of Kondo-like magnetic scattering induced in the heavy-Fermion like state. The irradiation effects are almost recovered after 500 deg. C annealing