75As-NMR/NQR Study of Iron Pnictide superconductor Ba1-xKxFe2As2
| Date/Time: | Thursday, 04 Oct 2012 - Thursday, 04 Oct 2012 |
|---|---|
| Location: | PHYSICS Hall Room 5 |
| Phone: | 515-294-5630 |
| Channel: | College of Liberal Arts and Sciences |
| Actions: | Download iCal/vCal | Email Reminder |
In superconducting SC state of Ba1-xKxFe2As2, it is recognized
that fully gaped structure is realized around for x ~ 0.4, and nodal gaped
structure for x ~ 1. In order to understand the change of SC gap structure
in hole over-doped region, we have performed 75As NMR and NQR on single
crystalline Ba1-xKxFe2As2 for 0.27 < x < 1. A simple two gap model analysis
of nuclear spin lattice relaxation rate 1/T1 shows that the larger SC gap
gradually decreases with increasing x from 0.27 to 1 and smaller SC gap
decreases rapidly and nearly vanishes for x > 0.6, where the electron
pockets at Brillouin zone disappear. The change of gap structure with
increasing x is very smooth.