Antiferromagnetism and Superconductivity: Magnetic Order in Y Sr2 Cu2.1 Ru0.9 O7.9

Author

H. A. Blackstead
William B. Yelon, Missouri University of Science and TechnologyFollow
M. Kornecki
M. P. Smylie
Q. Cai
J. Lamsal
V. P.S. Awana
S. Balamurugan
E. Takayama-Muromachi

Abstract

Superconducting (Tc ∼40 K) YSr₂Cu_2.1Ru_0.9O_7.9, prepared by a high-temperature high-pressure process, has been studied by electron spin resonance (ESR), neutron diffraction and superconducting quantum interference device magnetometry. Neutron diffraction confirms the antiferromagnetic ordering of the Ru atoms at TN-Ru ∼140 K, as reported by Lynn and Takagiwa ESR data show antiferromagnetic order that persists well above the Ru ordering temperature, with an intensity that peaks close to TN-Ru. the ESR data are very similar to those observed in GdSr₂Cu₂RuO₈ and YSr₂Cu_2.1Nb_0.9O_7.9. the apparent ferromagnetism observed at TN-Ru cannot arise from the strongly coupled c -axis-ordered Ru moments, which exhibit no canting; rather it appears to be due to a metamagnetic response of the cuprate planes induced by the Ru order. Magnetization data show the system as consisting of more than one magnetically ordered species; the magnetization is nonlinear well above TN-Ru, indicating that Cu atoms are ordered above that temperature. the neutron diffraction data at 16 K show additional intensity on the (0,0,1) reflection. Although Takagiwa attribute this to ferromagnetism, the polarized neutron data of Lynn on GdSr₂Cu₂RuO₈ rule out this explanation. These data, however, can be successfully modeled with ferromagnetic cuprate planes that are antiferromagnetically stacked. the refined Cu moment is found to be 0.4 (0.2) μB. the (0,0,1) magnetic Bragg peak is broadened relative to the nuclear peak, presumably due to a short correlation length of the magnetic domains along the c axis. the similarity of the magnetization curves in this compound and in YSr₂Cu_2.1Nb_0.9O_7.9 suggests that cuprate plane ordering is a common feature in this class of materials, which is very closely related to YBa₂Cu₃O_7-δ. © 2007 the American Physical Society.

Recommended Citation

H. A. Blackstead et al., "Antiferromagnetism and Superconductivity: Magnetic Order in Y Sr2 Cu2.1 Ru0.9 O7.9," Physical Review B - Condensed Matter and Materials Physics, vol. 76, no. 9, article no. 094507, American Physical Society, Sep 2007.

The definitive version is available at https://doi.org/10.1103/PhysRevB.76.094507

Department(s)

Physics

International Standard Serial Number (ISSN)

1550-235X; 1098-0121

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2024 American Physical Society, All rights reserved.

Publication Date

11 Sep 2007