The 63Cu Knight shifts have been measured for the heavily doped high-Tc superconductors TlSr2CaCu2O7-y, with Tc = 64 and 45 K. The spin part of the shift, Ks, is almost T-independent in the normal state and increases with decreasin g Tc. From the analysis of the anisotropy in Ks in both compounds, the transferred hyperfine field from the nearest-neighbor Cu spins has been deduced to be larger than that in YBa2Cu3O7, similar to the results for Tl2Ba2CuO6+y. A systemat ic correlation has been found in the heavily doped superconductors that the spin susceptibility and the nuclear quadrupole frequency increase with decreasing Tc, while 1/T1T is suppressed, as reported previously.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering