Thermodynamic and Transport Properties of CeMg2Cu9 under Pressure

We report the transport and thermodynamic properties under hydrostatic pressure in the antiferromagnetic Kondo compound CeMg 2 Cu 9 with a two-dimensional arrangement of Ce atoms. Magnetic specific heat C mag ( T ) shows a Schottky-type anomaly around 30 K originating from the crystal electric field (CEF) splitting of the 4 f state with the first excited level at Δ 1 / k B = 58 K and the second excited level at Δ 2 / k B = 136 K from the ground state. Electric resistivity shows a two-peak structure due to the Kondo effect on each CEF level around T 1 max = 3 K and T 2 max = 40 K. These peaks merge around 1.9 GPa with compression. With increasing pressure, Neel temperature T N initially increases and then changes to decrease. T N finally disappears at a quantum critical point P c = 2.4 GPa.