https://doi.org/10.1140/epjb/e2013-40019-2
Regular Article
Magnetic phase diagram and correlation between metamagnetism and superconductivity in Ru0.9Sr2YCu2.1O7.9
1
Institute for Superconducting and Electronic Materials, University
of Wollongong, Northfields
Avenue, Wollongong,
NSW
2522,
Australia
2
Bragg Institute, Australian Nuclear Science and Technology
Organization, New Illawarra
Road, Lucas
Heights, NSW
2234,
Australia
a e-mail: pan@uow.edu.au
Received:
9
January
2013
Received in final form:
19
April
2013
Published online:
19
June
2013
The magnetic superconductor Ru0.9Sr2YCu2.1O7.9 (Ru-1212Y) has been investigated using neutron diffraction under variable temperature and magnetic field. With the complementary information from magnetization measurements, we propose a magnetic phase diagram T-H for the Ru-1212 system. Uniaxial antiferromagnetic (AFM) order of 1.2μB/Ru atoms with moments parallel to the c-axis is found below the magnetic transition temperature at ~140 K in the absence of magnetic field. In addition, ferromagnetism (FM) in the ab-plane develops below ~120 K, but is suppressed at lower temperature by superconducting correlations. Externally applied magnetic fields cause Ru-moments to realign from the c-axis to the ab-plane, i.e. along the ⟨1,1,0⟩ direction, and induce ferromagnetism in the plane with ~1μB at 60 kOe. These observations of the weak ferromagnetism suppressed by superconductivity and the field-induced metamagnetic transition between AFM and FM demonstrate not only competing orders of superconductivity and magnetism, but also suggest a certain vortex dynamics contributing to these magnetic transitions.
Key words: Solid State and Materials
© EDP Sciences, Società Italiana di Fisica and Springer-Verlag, 2013