Muon spin rotation and infrared spectroscopy study of Ba1 -xNaxFe2As2
Abstract
The magnetic and superconducting properties of a series of underdoped Ba1 -xNaxFe2As2 (BNFA) single crystals with 0.19 ≤x ≤0.34 have been investigated with the complementary muon-spin-rotation (μ SR ) and infrared spectroscopy techniques. The focus has been on the different antiferromagnetic states in the underdoped regime and their competition with superconductivity, especially for the ones with a tetragonal crystal structure and a so-called double-Q magnetic order. Besides the collinear state with a spatially inhomogeneous spin-charge-density wave (i-SCDW) order at x =0.24 and 0.26, that was previously identified in BNFA, we obtained evidence for an orthomagnetic state with a "hedgehog"-type spin vortex crystal (SVC) structure at x =0.32 and 0.34. Whereas in the former i-SCDW state the infrared spectra show no sign of a superconducting response down to the lowest measured temperature of about 10 K, in the SVC state there is a strong superconducting response similar to the one at optimum doping. The magnetic order is strongly suppressed here in the superconducting state and at x =0.34 there is even a partial reentrance into a paramagnetic state at T ≪Tc .
- Publication:
-
Physical Review B
- Pub Date:
- June 2020
- DOI:
- 10.1103/PhysRevB.101.224515
- arXiv:
- arXiv:2004.13804
- Bibcode:
- 2020PhRvB.101v4515S
- Keywords:
-
- Condensed Matter - Superconductivity
- E-Print:
- 20 pages, 21 figures, 2 tables