Berlin 2012 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 27: Superconductivity: Cuprate Superconductors

TT 27.5: Vortrag

Mittwoch, 28. März 2012, 12:30–12:45, H 2053

Temperature behavior of the hole density of (Bi,Pb)-2212 single crystals — •Aliakbar Ghafari¹, Ahmad Kamal Ariffin², Christoph Janowitz¹, Helmut Dwelk¹, Alica Krapf¹, and Recardo Manzke¹ — ¹Institute of Physics, Humboldt University of Berlin, Newtonstr. 15, D-12489 Berlin, Germany — ²Dep. of Physics, Universiti Pendidikan Sultan Idris, 35900 Tanjong Malim, Malaysia

One of the most puzzling anomalies of high-T_C cuprates is the strong temperature dependence of the Hall coefficient (R_H) and the hole density (n_H). Gor’kov and Teitel’baum (GT) showed by using experimental data of La_2−xSr_xCuO₄ (LSCO) that the number of holes per Cu atom, n_H, changes with temperature according to n_H(T,x)=n₀(x)+n₁(x)exp(-Δ(x)/T) [1]. To clarify the temperature dependence of n_H we have determined n_H by x-ray absorption spectra (XAS) at the CuL₃ edge for nearly optimum and slightly underdoped (Bi,Pb)-2212 single crystals. Our results point out that the GT formula can not fit our data and therefore must be extended to the three terms.
L. P. Gor’kov and G. B. Teitel’baum, Phys. Rev. B 77, 180511 (2008)