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arXiv · 1910.12251

Relevance of magnetism to cuprate superconductivity: Lanthanides versus charge-compensated cuprates

Amit Keren·Wayne Crump·Ben P. P. Mallett·Shen V. Chong·Itai Keren·Hubertus Luetkens·Jeffery L. Tallon
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Abstract

We address what seemed to be a contradiction between the lanthanide series REBa$_2$Cu$_3$O$_y$ (RE123) and the charge-compensated series (Ca$_{x}$La$_{1-x}$)(Ba$_{1.75-x}$La$_{0.25+x} $)Cu$_{3}$O$_{y}$ (CLBLCO) regarding the superexchange ($J$) dependence of the maximum superconductivity (SC) critical temperature $T_c^{max}(J)$; RE and $x$ are implicit variables. This is done by measuring the Néel temperature and the temperature dependence of the magnetic order parameter for RE=Nd, Sm, Eu, Gd, Dy, Yb, Y, and for Y(BaSr)Cu$_3$O$_y$, at various very light dopings. The doping is determined by thermopower, and the magnetic properties by muon spin rotation. We find that the normalized-temperature dependence of the order parameter is identical for all RE123 in the undoped limit (with the exception of Gd123) implying identical out-of-plane magnetic coupling. The extrapolation of $T_N$ to zero doping suggests that, despite the variations in ionic radii, $J$ varies too weakly in this system to test the relation between SC and magnetism. This stands in contrast to CLBLCO where both $T_c^{max}$ and $T_N^{max}$ vary considerably in the undoped limit, and a positive correlation between the two quantities was observed.

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Amit Keren, Wayne Crump, Ben P. P. Mallett, Shen V. Chong, Itai Keren, Hubertus Luetkens, Jeffery L. Tallon. 2019-10-27. Relevance of magnetism to cuprate superconductivity: Lanthanides versus charge-compensated cuprates. https://doi.org/10.1103/physrevb.100.144512

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