Journal Article

FZJ-2018-01466

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Absence of magnetism in the superconductor B a 2 T i 2 F e 2 A s 4 O : Insights from inelastic neutron scattering measurements and ab initio calculations of phonon spectra

Zbiri, M. (Corresponding author) ; Jin, W. (Corresponding author)FZJ* ; Xiao, Y.FZJ* ; Sun, Y. ; Su, Y.FZJ* ; Demirdis, S.FZJ* ; Cao, G.

2017
Inst. Woodbury, NY

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Please use a persistent id in citations: http://hdl.handle.net/2128/17492  doi:10.1103/PhysRevB.95.174301

Abstract: Ba2Ti2Fe2As4O is a self-doped superconductor exhibiting a Tc∼21.5K and containing, distinctively with respect to other Fe-based superconductors, not only [Fe2As2] layers but also conducting [Ti2O] sheets. This compound exhibits a transition at T∗∼125K, which has tentatively been assigned in the literature to a possible density-wave order. However, the nature of this density wave (whether it is charge- or spin-induced) is still under debate. Magnetism in Ba2Ti2Fe2As4O has never been experimentally confirmed, which raises the question whether this superconductor might be nonmagnetic or exhibiting a very weak magnetism. Here, we report evidence from inelastic neutron scattering (INS) measurements and ab initio calculations of phonon spectra pointing towards a possible absence of magnetism in Ba2Ti2Fe2As4O. The INS measurements did not reveal any noticeable magnetic effects in Ba2Ti2Fe2As4O, within the accessible (Q, E) space. The effect of magnetism on describing phonon spectra was further investigated by performing ab initio calculations. In this context, nonmagnetic calculations reproduced well the measured phonon spectra. Therefore, our results indicate a nonmagnetic character of the superconductor Ba2Ti2Fe2As4O.

Keyword(s): Magnetic Materials (1st) ; Condensed Matter Physics (2nd) ; Magnetism (2nd)

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Contributing Institute(s):

1. JCNS-FRM-II (JCNS (München) ; Jülich Centre for Neutron Science JCNS (München) ; JCNS-FRM-II)
2. Streumethoden (JCNS-2)
3. Neutronenstreuung (Neutronenstreuung ; JCNS-1)

Research Program(s):

1. 6G15 - FRM II / MLZ (POF3-6G15) (POF3-6G15)
2. 6G4 - Jülich Centre for Neutron Research (JCNS) (POF3-623) (POF3-623)

Experiment(s):

1. Measurement at external facility

Appears in the scientific report 2018

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Database coverage:
; ; ; Current Contents - Physical, Chemical and Earth Sciences ; Ebsco Academic Search ; IF < 5 ; JCR ; SCOPUS ; Science Citation Index ; Science Citation Index Expanded ; Thomson Reuters Master Journal List ; Web of Science Core Collection

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