Resistivity Minimum in Dilute Itinerant Magnets

Resistivity minima are commonly seen in itinerant magnets and they are often attributed to the Kondo effect. However, recent experiments are revealing an increasing number of materials showing resistivity minima in absence of the Kondo singlet formation. In a previous work, we demonstrated that the Ruderman-Kittel-Kasuya-Yoshida (RKKY) interaction can produce a classical spin liquid state at finite temperature, whose resistivity increases with decreasing temperature. In this work, we investigate the robustness of the RKKY-induced resistivity upturn against site dilution. By series expansions and molecular dynamics simulation, we show that site dilution competes with thermal fluctuations and further stabilizes the upturn, which applies to both 2D and 3D dilute itinerant magnets. Under a magnetic field, the resistivity upturn is reduced due to suppression of the electron-spin scattering.