Heat transport of La$_{2-y}$Eu$_y$CuO$_4$ and La$_{1.88-y}$Eu$_y$Sr$_{0.12}$CuO$_4$ single crystals

X. F. Sun; Seiki Komiya; Yoichi Ando

doi:10.1103/PhysRevB.67.184512

paper

Heat transport of La $_{2 - y}$ Eu $_{y}$ CuO $_{4}$ and La $_{1.88 - y}$ Eu $_{y}$ Sr $_{0.12}$ CuO $_{4}$ single crystals

arXiv:cond-mat/0304126 · doi:10.1103/PhysRevB.67.184512

Abstract

To study the rare-earth doping effect on the phonon heat transport of La-based cuprates and shed light on the mechanism of phonon scattering, both $ab$ -plane and c-axis thermal conductivities ( $κ_{ab}$ and $κ_{c}$ ) are measured for La $_{2 - y}$ Eu $_{y}$ CuO $_{4}$ ( $y$ = 0, 0.02 and 0.2) and La $_{1.88 - y}$ Eu $_{y}$ Sr $_{0.12}$ CuO $_{4}$ ( $y$ = 0 and 0.2) single crystals. It is found that the phonon peak (at 20 -- 25 K) in $κ_{ab} (T)$ of La $_{2 - y}$ Eu $_{y}$ CuO $_{4}$ shows an anomalous Eu-doping dependence: it completely disappears for $y$ = 0.02, which is discussed to be due to the local lattice distortions around Eu dopants, and reappears for $y$ = 0.2 with much smaller peak magnitude compared to $y$ = 0 sample. In contrast to the strong suppression of the phonon peak in Eu-doped La $_{2}$ CuO $_{4}$ , Eu-doping to La $_{1.88}$ Sr $_{0.12}$ CuO $_{4}$ enhances the low- $T$ phonon heat transport that results in the reappearance of the phonon peak in this charge-carrier-doped system. The data clearly show that the establishment of static stripe phase rather than the structural change is responsible for the reappearance of phonon peak.

7 pages, 5 figures, final version published in Phys. Rev. B

Heat transport of La2−y​Euy​CuO4​ and La1.88−y​Euy​Sr0.12​CuO4​ single crystals

Abstract

Heat transport of La $_{2 - y}$ Eu $_{y}$ CuO $_{4}$ and La $_{1.88 - y}$ Eu $_{y}$ Sr $_{0.12}$ CuO $_{4}$ single crystals