Title :
Time dependent magnetic response in RBa2Cu3O 7-δ: effect of magnetic ordering
Author :
Földeaki, M. ; Dunlap, R.A. ; McHenry, M.E. ; O´Handley, R.C.
Author_Institution :
Dept. of Mater. Sci. & Eng., MIT, Cambridge, MA, USA
fDate :
9/1/1989 12:00:00 AM
Abstract :
High-Tc superconductors show time-dependent magnetic response due mainly to flux flow. In an investigation of the flux flow at temperatures far above any magnetic transition, no difference was found between the time-dependent response of Y1:2:3 and R1:2:3 (R=Gd, Dy), leading to the conclusion that the paramagnetic susceptibility does not contribute to the time dependence in general. On the contrary, near the antiferromagnetic ordering temperature of Gd1:2:3 and in the region of reduced local moment in Dy1:2:3, an anomalous time dependence is observed which can only be explained by assuming a time-dependent paramagnetic susceptibility. The susceptibility can be interpreted by the assumption of a time-dependent magnetic order parameter, which is an unusual feature of magnetic transitions. A possible explanation is spin-glass-like behavior of the local moments
Keywords :
antiferromagnetic properties of substances; barium compounds; dysprosium compounds; flux flow; gadolinium compounds; high-temperature superconductors; magnetic superconductors; magnetic susceptibility; magnetic transitions; paramagnetic-antiferromagnetic transitions; spin glasses; DyBa2Cu3O7-δ; GdBa2Cu3O7-δ; antiferromagnetic ordering temperature; flux flow; high temperature superconductor; local moment; magnetic order parameter; magnetic ordering effect; magnetic transition; paramagnetic susceptibility; spin glass; time dependent magnetic response; Antiferromagnetic materials; Magnetic field measurement; Magnetic flux; Magnetization; Paramagnetic materials; Superconducting magnets; Superconducting transition temperature; Temperature dependence; Temperature distribution; Time factors;
Journal_Title :
Magnetics, IEEE Transactions on
