【摘要】 测量了高质量的单晶膜La2 -xSrxCuO4(x =0 10 ,0 2 0 ,0 2 5 )的电阻率和热电势 .La1 9Sr0 1 CuO4电阻率呈现S型行为 ,表明存在一个赝能隙 ,在赝能隙态可以用公式 ρ =ρ0 +βexp(-Δ T)很好地拟合 .热电势的测量表明 ,在超导转变前样品的残余热电势值非常小 ,这是膜的高质量引起的 ,三个样品在 2 0 0K以上都出现一个宽峰 ,对其进行了一些理论模型分析 ,并与电子型超导体热电势结果作了比较 .更多还原

【Abstract】 The resistivity and thermopower for La 2-xSr xCuO 4(x=0.10, 0.20,0.25) thin film were measured. An S-shape behaviour was found in resistivity of the La 1.9Sr 0.1CuO 4 sample, indicating a pseudogap. In the pseudogap state, the value of resistivity can be fitted well by formula ρ=ρ 0+βexp(-Δ/T). The magnitude of thermopower became very small before the superconducting transition, which means the high quality of the thin films. All the samples showed a hump above 200K. The results are analyzed with some theoretcal models and compared with the data of electronic superconductor.更多还原