%0 Generic %1 salemsuguijr2012magnetic %A Salem-Sugui Jr, S. %A Alvarenga, A. D. %A Mosqueira, J. %A Dancausa, J. D. %A Mejia, C. Salazar %A Sinnecker, E. %A Luo, Huiqian %A Wen, Hai-Hu %D 2012 %K BKT highTc magnetisation_above_Tc %R 10.1088/0953-2048/25/10/105004 %T Magnetic phase diagram of the layered superconductor Bi2+xSr2-xCuO6+\delta (Bi2201) with Tc~7 K %U http://arxiv.org/abs/1208.2605 %X We report on magnetization measurements performed on a single crystal of Bi2+xSr2-xCuO6+\delta with Tc\sim7 K for H||c-axis. The isofield M(T) curves show a large reversible region, with a pronounced rounding effect as M approaches zero which prevents the determination of Tc(H). Deviations from the linear behavior of magnetisation near Tc(H) are studied through the asymptotic behavior of $-M(T)\sim(T-Ta)^m$, where m is an exponent and Ta an apparent temperature transition. Values of m deviates from the expected mean field value, 1/2, suggesting the importance of phase fluctuations. Resulting values of Ta, interpreted as the onset of phase correlations, decrease as field increases showing an upward curvature. Values of Tc(H) are obtained through a two-dimensional critical scaling analysis obeyed by many M(T) curves. The resulting phase diagram do not show upward curvature and lies below the Ta(H) line. The value of Hc2(0) estimated from the initial slope $H_c2/dT is twice the value suggested by the phase diagram. Amplitude fluctuations above Ta(H) are explained in terms of a Ginzburg-Landau approach extended to high reduced temperatures and magnetic fields by the introduction of a total-energy cutoff in the fluctuation spectrum.

@misc{salemsuguijr2012magnetic, abstract = {We report on magnetization measurements performed on a single crystal of Bi{2+x}Sr{2-x}CuO{6+\delta} with Tc\sim7 K for H||c-axis. The isofield M(T) curves show a large reversible region, with a pronounced rounding effect as M approaches zero which prevents the determination of Tc(H). Deviations from the linear behavior of magnetisation near Tc(H) are studied through the asymptotic behavior of $\sqrt{-M(T)}\sim(T-Ta)^m$, where m is an exponent and Ta an apparent temperature transition. Values of m deviates from the expected mean field value, 1/2, suggesting the importance of phase fluctuations. Resulting values of Ta, interpreted as the onset of phase correlations, decrease as field increases showing an upward curvature. Values of Tc(H) are obtained through a two-dimensional critical scaling analysis obeyed by many M(T) curves. The resulting phase diagram do not show upward curvature and lies below the Ta(H) line. The value of H{c2}(0) estimated from the initial slope $H_{c2}/dT is twice the value suggested by the phase diagram. Amplitude fluctuations above Ta(H) are explained in terms of a Ginzburg-Landau approach extended to high reduced temperatures and magnetic fields by the introduction of a total-energy cutoff in the fluctuation spectrum.}, added-at = {2012-08-15T17:25:22.000+0200}, author = {Salem-Sugui Jr, S. and Alvarenga, A. D. and Mosqueira, J. and Dancausa, J. D. and Mejia, C. Salazar and Sinnecker, E. and Luo, Huiqian and Wen, Hai-Hu}, biburl = {https://www.bibsonomy.org/bibtex/2a619d202cbc93737033dd052b43724d4/vakaryuk}, description = {Magnetic phase diagram of the layered superconductor Bi{2+x}Sr{2-x}CuO{6+\delta} (Bi2201) with Tc~7 K}, doi = {10.1088/0953-2048/25/10/105004}, interhash = {96136dcbeead299fa776d21657f71d2a}, intrahash = {a619d202cbc93737033dd052b43724d4}, keywords = {BKT highTc magnetisation_above_Tc}, note = {cite arxiv:1208.2605 Comment: 6 pages, 4 figures}, timestamp = {2012-08-15T17:25:22.000+0200}, title = {Magnetic phase diagram of the layered superconductor Bi{2+x}Sr{2-x}CuO{6+\delta} (Bi2201) with Tc~7 K}, url = {http://arxiv.org/abs/1208.2605}, year = 2012 }