Abstract
Two-dimensional van der Waals magnets with multiple functionalities are becoming increasingly important for emerging technologies in spintronics and valleytronics. Application of external pressure is one method to cleanly explore the underlying physical mechanisms of the intrinsic magnetism. In this paper, the magnetic, electronic, and structural properties of van der Waals-layered, Fe-deficient Fe3-xGeTe2 are investigated. Magnetotransport measurements show a monotonic decrease in the Curie temperature (TC) and the magnetic moment with increasing pressure up to 13.9 GPa. The electrical resistance of Fe3-xGeTe2 shows a change from metallic to a seemingly nonmetallic behavior with increasing pressure. High-pressure angle dispersive powder x-ray diffraction shows a monotonic compression of the unit cell and a reduction of the volume by ∼25% with no evidence of structural phase changes up to 29.4(4) GPa. We suggest that the decrease in the TC due to pressure results from increased intralayer coupling and delocalization that leads to a change in the exchange interaction.
| Original language | English |
|---|---|
| Article number | 054405 |
| Journal | Physical Review B |
| Volume | 102 |
| Issue number | 5 |
| DOIs | |
| State | Published - Aug 1 2020 |
Funding
This work was performed under the auspices of the U.S. Department of Energy (DOE) by LLNL under Contract No. DE-AC52-07NA27344. Part of the funding was provided through the LLNL Lawrence Graduate Scholar Program. D.J.O. acknowledges support from the GEM National Consortium Ph.D. Fellowship. Portions of this work were performed at HPCAT (Sector 16), Advanced Photon Source, Argonne National Laboratory (ANL). HPCAT operations are supported by DOE-NNSA's Office of Experimental Sciences. The APS is a U.S. DOE of Science User Facility operated for the DOE Office of Science by ANL under Contract No. DE-AC02-06CH11357. D.W., J.E.G., and R.K.K. acknowledge support from the Center for Emergent Materials, an NSF MRSEC under Grant No. DMR-1420451. Z.E.B. and R.J.Z. acknowledge support from NSF Grant No. DMR-1609855. We thank J. Beckham, J. R. I. Lee (LLNL), and C. Park (HPCAT) for technical assistance. D.J.O. was supported by NRC/NRL while finalizing the paper.
| Funders | Funder number |
|---|---|
| DOE-NNSA's Office of Experimental Sciences | |
| National Science Foundation | DMR-1609855 |
| U.S. Department of Energy | |
| Office of Science | |
| Argonne National Laboratory | DE-AC02-06CH11357 |
| Lawrence Livermore National Laboratory | DE-AC52-07NA27344 |
| U.S. Naval Research Laboratory | |
| National Research Council | |
| Materials Research Science and Engineering Center, Harvard University | DMR-1420451 |