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arXiv · 0711.3509

Pressure dependence of the oxygen isotope effect in YBa$_2$Cu$_4$O$_8$

N. Suresh·J. G. Storey·G. V. M. Williams·J. L. Tallon
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Abstract

We have carried out measurements of the pressure dependence to 1.2 GPa of the oxygen isotope effect on $T_c$ in the high-$T_c$ superconductor YBa$_2$Cu$_4$O$_8$ using a clamp cell in a SQUID magnetometer. This compound lies close to, but just above, the 1/8$^{th}$ doping point where in La$_{2-x}$Sr$_x$CuO$_4$ marked anomalies in isotope effects occur. Both isotopes show the same very large pressure dependence of $T_c$ with the result that the isotope exponent remains low ($\sim$0.08) but increases slightly with increasing pressure. This is discussed in terms of stripe suppression, a competing pseudogap and the effect of superconducting fluctuations.

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N. Suresh, J. G. Storey, G. V. M. Williams, J. L. Tallon. 2007-11-22. Pressure dependence of the oxygen isotope effect in YBa$_2$Cu$_4$O$_8$. https://doi.org/10.1103/physrevb.78.100503

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