Scaling behaviour of the in-plane thermopower in Bi₂Sr₂RCu₂O₈(R = Ca, Y, Pr, Dy and Er)

Abstract

Single crystals of insulating Bi2Sr2RCu2O8 (R = Dy, Er, Y and Ca0.5Er0.5) and superconducting Bi2Sr2Ca1-xPrxCu2O8 (x = 0, 0.10, 0.25, 0.36 and 0.42) were prepared, and the thermopower S(T) along the CuO2 plane was measured from 4.2 to 420 K. All of the thermopowers including those for the insulators are roughly expressed as A-BT above a certain temperature Tscale, where A and B are positive constants. S(T)/S(Tscale) for all of the samples falls onto a single curve as a function of T/Tscale. Since Tscale is close to the pseudogap temperature for the superconductors, this scaling offers a rough estimate of the pseudogap temperature of high-Tc superconductors. The present study further suggests that the parent insulators have a pseudogap above room temperature.

Anomalous thermopower in the organic compoundθ−(BEDT-TTF)2RbM(SCN)Abdel‐Jawad1, Terasaki2, Mori3 et al. 2009Phys. Rev. B4010View full textAdd to dashboardCite

“…We can confirm these trends by quenching the material so as to freeze the high-temperature phase and extend and S b to temperatures as low as 50 K. Note that S b was unable to be measured accurately from 130 to 190 K as the rapidly cooled state decomposes too quickly to the equilibrium phase. The anomalous nature of the temperature dependence of S b is similar to the case of the normal-state thermopower of the high-T c copper oxides 15,16 and to the thermopower of the misfit cobalt oxides. 17 However a few very important differences between these systems exist.…”

Two Pseudogap Behavior in La2-xSrxCuO4: Thermoelectric Power at High Temperature

“…TEP of other cuprates [6][7][8][9] would be related to the small pseudogap phenomena. Yanase [34] proposed that the strong superconducting fluctuation induces the small pseudogap and suppresses the antiferromagnetic (AFM) spin fluctuation.…”

“…To understand the anomalous transport mechanisms of cuprates, the pseudogap phenomena have been extensively studied by Hall effect [4], resistivity [5] as well as TEP [6][7][8][9][10]. Interestingly it was found that the temperature dependence of TEP for various doping levels shows linear-T dependence above a peak temperature, T p , and on the basis of this temperature T p , TEP can be scaled in a universal curve [6].…”

Chemical potential shift in lightly doped to overdopedBi2Sr2Ca

“…Recently, high quality crystals of heavily underdoped BSCCO were systematically synthesized by rare-earth ͑R͒ substitution for Ca and the doping dependence of thermodynamic and transport properties has been studied. 11,12 In this paper, we report on a core-level photoemission study of the chemical potential shift ⌬ in those Bi 2 Sr 2 Ca 1Ϫx R x Cu 2 O 8ϩy crystals as a function of doped hole concentration. The chemical potential shift was estimated from the core-level shifts as in the previous studies 3,5,13 utilizing the fact that the energies of core levels are measured in reference to in photoemission experiments.…”