1 Institute of Low Temperature and Structure Research, Polish Ac.
Penetration depth varies linearly with temperature for low temperature region.
For zinc-doped, underdoped the temperature dependences of Penetration depths tan be described by power laws, but with exponents n varying linearly with Substituent content. We found that the penetration-depth anisotropy is dependent on Substituent content in decreasing to a minimum at and increasing for higher Substitutions and tan be described by a quadratic function. Our results strongly suggest that both the effective mass and the density of Charge carriers must be taken into account in theories describing high-temperature superconductivity. LNP 0545, p. 230 ff.