We have investigated systematically by magnetization measurements the penetration depth λ of HgBa2CuO4 + δ with doping 0.1 ≤ δ ≤ 0.3, ranging from the underdoped region of δ < 0.22 to the overdoped region of δ > 0.22. The penetration depth was found to vary with temperature quadratically for the underdoped samples below the transition temperature (Tc) over the entire temperature region examined, while linearly for the optimally doped and overdoped samples below 0.5 Tc. The observation suggests that the temperature dependence of λ is affected by doping in a complex way and its inference to the pairing symmetry should be taken only with extreme care.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics