Magnetic structure and phase stability of the van der Waals bonded ferromagnet Fe3-xGeTe2

Autor: May, Andrew F., Calder, Stuart, Cantoni, Claudia, Cao, Huibo, McGuire, Michael A.
Rok vydání: 2015
Předmět:
Zdroj: Phys. Rev. B 93, 014411 (2016)
Druh dokumentu: Working Paper
DOI: 10.1103/PhysRevB.93.014411
Popis: The magnetic structure and phase diagram of the layered ferromagnetic compound Fe$_3$GeTe$_2$ has been investigated by a combination of synthesis, x-ray and neutron diffraction, high resolution microscopy, and magnetization measurements. Single crystals were synthesized by self-flux reactions, and single crystal neutron diffraction finds ferromagnetic order with moments of 1.11(5)$\mu_B$/Fe aligned along the $c$-axis at 4K. These flux-grown crystals have a lower Curie temperature $T_{\textrm{c}}\approx$150K compared to crystals previously grown by vapor transport ($T_{\textrm{c}}$=220K). The difference is a reduced Fe content in the flux grown crystals, as illustrated by the behavior observed in a series of polycrystalline samples. As Fe-content decreases, so does the Curie temperature, magnetic anisotropy, and net magnetization. In addition, Hall effect and thermoelectric measurements on flux-grown crystals suggest multiple carrier types contribute to electrical transport in Fe$_{3-x}$GeTe$_2$ and structurally-similar Ni$_{3-x}$GeTe$_2$.
Comment: accepted version to be published in PRB; corrections made, includes Supplemental information
Databáze: arXiv