Coexistence of superconductivity and a charge density wave in LaPt2(Si1−xGex)2 (0   x   0.5)

Interplay between a charge density wave (CDW) and superconductivity in LaPt2(Si1−xGex)2 has been studied by electrical transport and magnetic measurements. LaPt2Si2 crystallizes in CaBe2Ge2 type structure which shows a first order structural phase transition from tetragonal to orthorhombic accompanied by a CDW transition at 112 K and superconducting transition at around 1.22 K as confirmed by temperature dependence of resistivity and magnetic measurements. For 2% doping of germanium, while the CDW temperature TCDW decreases, the superconducting transition temperature TC shows an increase. TCDW increases for 5% doping of germanium and the superconducting transition decreases. These findings demonstrate the competing nature of a CDW and superconductivity.