Thermoelectric power and carrier concentration of La 2−x Sr x CuO 4 (0.03 <x <0.17) single crystals

Thermoelectric power (S) measurements have been systematically investigated in high-quality La 2−x -Sr x -CuO 4 single crystals with different Sr concentrations ( x = 0.03, 0.05, 0.07, 0.1, 0.12). In this doping range studied, S remains positive, and with the increase of Sr concentration, room-temperature thermoelectric power S (290 K) decreases. An empirical formula which presents a relationship between hole concentration P and room-temperature thermoelectric power S (290 K) is reported in this note. Based on the theory of metallic diffusion model, the experimental results are discussed.