Ferromagnetic transition ofSrRuO3in nanometer thick bilayers withYBa2Cu3Oy,La1.88Sr0.12CuO4−y, Au, and Cr: Signature of injected carriers in the pseudogap regime

2007/07/17 by G. Aharonovich, G. Koren, E. Polturak
Chemistry · Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Chemistry #Condensed matter physics #Crystallography #Ferromagnetism #Magnetic and transport properties of perovskites and related materials #Magnetization #Physics #Physics of Superconductivity and Magnetism #Quantum mechanics #cond-mat.str-el #cond-mat.supr-con

paper · pdf · doi:10.1103/physrevb.76.224514

published in Physical Review B 76(22) (American Physical Society) · 9 figures

arxiv created 2007/07/17 · openalex publication_date 2007/12/13 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05

Abstract

The hypothesis regarding the existence of uncorrelated preformed pairs in the pseudogap regime of superconducting YBa₂Cu₃O_y is tested experimentally using bilayers of YBa₂Cu₃O_y and the itinerant ferromagnet SrRuO₃. In our study, we monitor the influence of YBa₂Cu₃O_y on T_p, the ferromagnetic ordering temperature of SrRuO₃. Here, T_p is the temperature of maximum dM∕dT or dR∕dT, where M and R are the magnetization and resistance of SrRuO₃, respectively. We compare the results with similar measurements carried out on bilayers of La_1.88Sr_0.12CuO_4\ensuremath-y, Au, and Cr with SrRuO₃. We find that in bilayers made of underdoped 10\phantom\rule0.3em0exnm YBa₂Cu₃O_y∕5\phantom\rule0.3em0exnm SrRuO₃, the T_p values are shifted to lower temperatures by up to 6--8\phantom\rule0.3em0exK as compared to T_p\ensuremath≈140\phantom\rule0.3em0exK of the 5\phantom\rule0.3em0exnm thick reference SrRuO₃ film. In contrast, in the other type of bilayers, which are not in the pseudogap regime near T_p, only a smaller shift of up to \ifmmode±\else\textpm\fi2\phantom\rule0.3em0exK is observed. These differences are discussed in terms of a proximity effect, where carriers from the YBa₂Cu₃O_y layer are injected into the SrRuO₃ layer and vice versa. We suggest that correlated electrons in the pseudogap regime of YBa₂Cu₃O_y are responsible for the observed large T_p shifts.

Citations

• Signature of a crossed Andreev reflection effect in the magnetic response ofYBa2Cu3O7−δjunctions with the itinerant ferromagnetSrRuO3
• Ferromagnetic/superconducting bilayer structure: A model system for spin diffusion length estimation
• The pseudogap in high-temperature superconductors: an experimental survey
• Scanning tunneling spectroscopy characterization of the pseudogap and thex=18anomaly inLa2−xSrxCuO4thin films