REDUCTION OF THE ELECTRONIC COEFFICIENT OF THE SPECIFIC-HEAT AROUND X=0.065 IN (LA1-XBAX)2CUO4

Low-temperature specific heat was measured on (La1-xBax)2CuO4 system by using the well-characterized samples. The sample with x=0.065 exhibits the transition from the low-temperature orthorhombic phase to the low-temperature tetragonal one around 60 K and is in the normal state over almost whole volume down to the lowest temperature investigated. It is found from the specific heat results that the electronic coefficient as a function of x is fairly reduced around x=0.065. This result strongly suggests that the orthorhombic-to-tetragonal phase transition reduces significantly the density of states at the Fermi level. © 1990.