Probing the connections between superconductivity, stripe order, and structure in La 1.905 Ba 0.095 Cu 1−y Zn y O 4
Year: 2012
Type: article
Abstract: The superconducting system La${}_{2\ensuremath{-}x}$Ba${}_{x}$CuO${}_{4}$ is known to show a minimum in the transition temperature ${T}_{c}$ at $x=\frac{1}{8}$ where maximal stripe order is pinned by the anisotropy within the CuO${}_{2}$ planes that occurs in the low-temperature-tetragonal (LTT) crystal structure. For $x=0.095$, where ${T}_{c}$ reaches its maximum value of 32 K, there is a roughly coincident structural transition to a phase that is very close to LTT. Here, we present a neutron scattering study of the structural transition, and demonstrate how features of it correlate with anomalies in the magnetic susceptibility, electrical resistivity, thermal conductivity, and thermoelectric power. We also present measurements on a crystal with 1$%$ Zn substituted for Cu, which reduces ${T}_{c}$ to 17 K, enhances the spin stripe order, but has much less effect on the structural transition. We make the case that the structural transition correlates with a reduction of the Josephson coupling between the CuO${}_{2}$ layers, which interrupts the growth of the superconducting order. We also discuss evidence for two-dimensional superconducting fluctuations in the normal state, analyze the effective magnetic moment per Zn impurity, and consider the significance of the anomalous thermopower often reported in the stripe-ordered phase.
Source: Physical Review B
Institutions: Brookhaven National Laboratory, University of California, Berkeley, City College of New York, Stony Brook University, Oak Ridge National Laboratory, Iowa State University, Ames National Laboratory, National Institute of Standards and Technology, NIST Center for Neutron Research, University of Maryland, College Park
Language: Latvian
Subfield: Condensed Matter Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W1783740468