In high-Tc superconductors (La1–xMx)2CuO4 (M = Ba, Sr), it has been reported that the heat capacity has a nonzero coefficient γ in the temperature linear term. We investigated the detailed dependence of γ on Ba doping. It was confirmed that γ becomes zero for undoped La2CuO4. With increasing Ba concentration x, γ increases markedly up to x=0.02 where the magnetic order almost disappears, while it decreases as superconductivity starts to appear and then has a minimum around x=0.04. With further increasing x, γ increases again. These results may be due to a combined effect of two different contributions to γ.
ASJC Scopus subject areas
- Physics and Astronomy(all)