title: A temperature dependent tunneling study of the spin density wave gap in EuFe2As2 single crystals.
abstract: We report temperature dependent scanning tunneling microscopy and spectroscopy measurements on single crystals of EuFe2As2 in the 15-292 K temperature range. The in situ cleaved crystals show atomic terraces with homogeneous tunnel spectra that correlate well with the spin density wave (SDW) transition at a temperature, TSDW ≈ 186 K. Above TSDW the local tunnel spectra show a small depression in the density of states (DOS) near the Fermi energy (EF). The gap becomes more pronounced upon entering the SDW state with a gap value ∼90 meV at 15 K. However, the zero bias conductance remains finite down to 15 K indicating a finite DOS at the EF in the SDW phase. Furthermore, no noticeable change is observed in the DOS at the antiferromagnetic ordering transition of Eu(2+) moments at 19 K.
authors: Department of Physics, Indian Institute of Technology Kanpur, Kanpur 208016, India.
authors: Anirban
authors: A
authors: Dutta
authors: Anupam
authors: Z
authors: Z
authors: Hossain
authors: Anjan K
authors: AK
authors: Gupta
mesh_terms: D001151:Arsenic / Q000737:chemistry*; D003461:Crystallography; D005063:Europium / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D016252:Microscopy, Scanning Tunneling / Q000379:methods*; D008956:Models, Chemical; D013696:Temperature
chemical_list: D005063:Europium; D007501:Iron; D001151:Arsenic