Fermi-liquid properties of the heavy fermion systems YbT2Zn20 (T = Ir, Rh and Co) under pressure

We have measured the electrical resistivity of YbT2Zn20 (T = Ir, Rh) single crystals under pressure up to 2.4 GPa. We found that the resistivity of both compounds shows a pronounced maximum Tmax under pressure as seen in YbCo2Zn20 at ambient pressure. The temperature Tmax decreases with increasing pressure, reflecting the lowering of the Kondo temperature TK. Low temperature resistivity behaves as expected for a conventional Landau Fermi liquid ρ = ρ0 + AT2. The A coefficient is strongly enhanced upon applying pressure and can be related to the Tmax by A−1/2 Tmax. This relation holds for YbT2Zn20 (T = Ir, Rh and Co) compounds in the pressure range investigated here, suggesting the validity of the Fermi liquid description in this system.