Title: Magnetic excitations in the quasi-two-dimensional ferromagnet Fe3-x GeTe2 measured with inelastic neutron scattering

Journal Article · · Physical Review B

Fe3-xGeTe2 is an itinerant ferromagnet made up of of two-dimensional layers weakly connected by van der Waals bonding that shows a variety of intriguing phenomena. Inelastic neutron scattering measurements on bulk single crystals of Fe2.75GeTe2 were performed to quantify the magnetic exchange interaction energies and anisotropy. The observed inelastic excitations, which extend to a maximum energy of ~75 meV, are indicative of dominant in-plane correlations with negligible magnetic interactions between the layers. A spin gap of 3.7 meV is observed, allowing a measure of the magnetic anisotropy. The excitations are damped, reflective of both the magnetic site occupancy reduction of 25% on one Fe sublattice and the itinerant interactions. A minimal model is employed to describe the excitation spectra and extract magnetic exchange interaction values. The temperature evolution of the excitations are probed and correlations shown to persist above Tc, further indicating the low-dimensional nature of the magnetism.

Research Organization:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Basic Energy Sciences (BES); USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Grant/Contract Number:
AC05-00OR22725
OSTI ID:
1506797
Journal Information:
Physical Review B, Journal Name: Physical Review B Journal Issue: 9 Vol. 99; ISSN 2469-9950; ISSN PRBMDO
Publisher:
American Physical Society (APS)Copyright Statement
Country of Publication:
United States
Language:
English

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