Abstract
From magnetization measurements we provide evidence that the ferromagnetic superconductor ${\mathrm{RuSr}}_{2}{\mathrm{GdCu}}_{2}{\mathrm{O}}_{8}$ with ${T}_{c}\ensuremath{\approx}45\mathrm{K}$ and ${T}_{M}\ensuremath{\approx}135\mathrm{K}$ exhibits a sizeable diamagnetic signal at low temperature $(Tl{T}^{\mathrm{ms}}=30\mathrm{K})$ and low magnetic field ${(H}^{\mathrm{ext}}l30l30g\mathrm{Oe}),$ corresponding to a bulk Meissner phase. We argue that a recent negative report [C. W. Chu et al., cond-mat/9910056 (unpublished)] regarding the Meissner effect in Ru-1212 can be explained by impurity scattering or grain-size effects. At intermediate temperatures, ${T}^{\mathrm{ms}}lTl{T}_{c},$ we observe unique thermal hysteresis effects which are characteristic of a spontaneous vortex phase.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
