Enhanced Critical Temperatures In The Strongly Overdoped Iron-Based Superconductors Afe(2)As(2) (A = K, Cs, Rb) Observed By Point Contacts

A remarkable several times increase (up to 10 K) of the superconducting critical temperature T-c has been observed in point contacts created on the base of single crystals AFe(2)As(2) (A = K, Cs, Rb). Possible reasons for such a T-c increase in point contacts are briefly discussed on a qualitative level. Among them, it is most likely attributed to interfacial carrier doping and/or uniaxial non-homogeneous pressure arising when the contact is created.