Publication Date

6-21-2019

Department

Ames Laboratory; Physics and Astronomy

Campus Units

Physics and Astronomy, Ames Laboratory

OSTI ID+

1545207

Report Number

IS-J 9978; IS-J 9906

DOI

10.1103/PhysRevB.99.220404

Journal Title

Physical Review B

Volume Number

99

Issue Number

22

First Page

220404(R)

Abstract

Employing elastic and inelastic neutron scattering (INS) techniques, we report on the microscopic properties of the ferromagnetism in the dilute magnetic topological insulator (Bi0.95Mn0.05)2 Te3. Neutron diffraction of polycrystalline samples shows the ferromagnetic (FM) ordering is long range within the basal plane, and mainly two dimensional (2D) in character with short-range correlations between layers below T C ≈ 13 K. Remarkably, we observe gapped and collective magnetic excitations in this dilute magnetic system. The excitations appear typical of quasi-2D FM systems despite the severe broadening of short-wavelength magnons which is expected from the random spatial distribution of Mn atoms in the Bi planes. A detailed analysis of the INS provides the average values for exchange couplings which are consistent with reports of carrier-mediated interactions.

DOE Contract Number(s)

AC02-07CH11358; AC05-00OR22725

Language

en

Department of Energy Subject Categories

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY

Publisher

Iowa State University Digital Repository, Ames IA (United States)

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