Direct observation of the energy gain underpinning ferromagnetic superexchange in the electronic structure of CrGeTe3

DOI: 10.1103/PhysRevB.101.205125

Authors: Matthew D. Watson (University of St Andrews) , Igor Markovic (University of St Andrews; Max Planck Institute for Chemical Physics of Solids) , Federico Mazzola (University of St Andrews) , Akhil Rajan (University of St Andrews) , Edgar A. Morales (University of St Andrews; Max Planck Institute for Chemical Physics of Solids) , David Burn (Diamond Light Source) , Thorsten Hesjedal (University of Oxford) , Gerrit Van Der Laan (Diamond Light Source) , Saumya Mukherjee (Diamond Light Source) , Timur K. Kim (Diamond Light Source) , Chiara Bigi (Istituto Officina dei Materiali (IOM)-CNR; University of Milano) , Ivana Vobornik (Istituto Officina dei Materiali (IOM)-CNR) , Monica Ciomaga Hatnean (University of Warwick) , Geetha Balakrishnan (University of Warwick) , Philip D. C. King (University of St Andrews)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Physical Review B , VOL 101

State: Published (Approved)
Published: May 2020
Diamond Proposal Number(s): 21986 , 22794 , 23785

Abstract: We investigate the temperature-dependent electronic structure of the van der Waals ferromagnet, CrGeTe3. Using angle-resolved photoemission spectroscopy, we identify atomic- and orbital-specific band shifts upon cooling through TC. From these, together with x-ray absorption spectroscopy and x-ray magnetic circular dichroism measurements, we identify the states created by a covalent bond between the Te 5p and the Cr eg orbitals as the primary driver of the ferromagnetic ordering in this system, while it is the Cr t2g states that carry the majority of the spin moment. The t2g states furthermore exhibit a marked bandwidth increase and a remarkable lifetime enhancement upon entering the ordered phase, pointing to a delicate interplay between localized and itinerant states in this family of layered ferromagnets.

Journal Keywords: Exchange interaction; Magnetism; Ferromagnets; Van der Waals systems; Angle-resolved photoemission spectroscopy; X-ray magnetic circular dichroism

Diamond Keywords: Ferromagnetism

Subject Areas: Materials, Physics, Energy


Instruments: I05-ARPES , I10-Beamline for Advanced Dichroism - scattering

Other Facilities: APE beamline at Elettra

Added On: 26/05/2020 09:20

Discipline Tags:

Quantum Materials Physics Hard condensed matter - structures Magnetism Materials Science

Technical Tags:

Spectroscopy Angle Resolved Photoemission Spectroscopy (ARPES) Circular Dichroism (CD) X-ray Absorption Spectroscopy (XAS) X-ray Magnetic Circular Dichroism (XMCD)