Pressure and 75As-NMR/NQR studies of iron pnictide superconductor Ba1-xKxFe2As2
|Date/Time:||Wednesday, 06 Oct 2010 from 1:10 pm to 2:00 pm|
|Location:||Room A401 Zaffarano|
|Channel:||Condensed Matter Physics|
We have measured electrical resistivity under pressure P and 75As NMR on single crystal BaFe2As2 and (Ba1-xKx)Fe2As2 to elucidate mechanism of antiferromagnetic/superconducting phase transition in BaFe2As2.
This system is an antiferromagnet, AF, which shows superconductivity by applying P or by a carrier doping of K for Ba. From high P resistivity measurements, we understood that the transition was highly sensitive to the P homogeneity. 75As NMR study in (Ba1-xKx)Fe2As2 shows existence of large AF spin fluctuations in tetragonal phase having a superconducting ground state. The AF spin fluctuations decrease gradually with increasing K concentration. The magnetic and superconducting properties of KFe2As2 were carefully studied together with specific heat data.