8 research outputs found
Tailoring Dzyaloshinskii-Moriya interaction in a transition metal dichalcogenide by dual-intercalation
Dzyaloshinskii-Moriya interaction (DMI) is vital to form various chiral spin
textures, novel behaviors of magnons and permits their potential applications
in energy-efficient spintronic devices. Here, we realize a sizable bulk DMI in
a transition metal dichalcogenide (TMD) 2H-TaS2 by intercalating Fe atoms,
which form the chiral supercells with broken spatial inversion symmetry and
also act as the source of magnetic orderings. Using a newly developed protonic
gate technology, gate-controlled protons intercalation could further change the
carrier density and intensely tune DMI via the Ruderman-Kittel-Kasuya-Yosida
mechanism. The resultant giant topological Hall resistivity of 1.4 uohm.cm at
-5.2V (about 460% of the zero-bias value) is larger than most of the known
magnetic materials. Theoretical analysis indicates that such a large
topological Hall effect originates from the two-dimensional Bloch-type chiral
spin textures stabilized by DMI, while the large anomalous Hall effect comes
from the gapped Dirac nodal lines by spin-orbit interaction. Dual-intercalation
in 2HTaS2 provides a model system to reveal the nature of DMI in the large
family of TMDs and a promising way of gate tuning of DMI, which further enables
an electrical control of the chiral spin textures and related electromagnetic
phenomena.Comment: 21 pages, 4 figure
Room temperature magnetic phase transition in an electrically-tuned van der Waals ferromagnet
Finding tunable van der Waals (vdW) ferromagnets that operate at above room
temperature is an important research focus in physics and materials science.
Most vdW magnets are only intrinsically magnetic far below room temperature and
magnetism with square-shaped hysteresis at room-temperature has yet to be
observed. Here, we report magnetism in a quasi-2D magnet Cr1.2Te2 observed at
room temperature (290 K). This magnetism was tuned via a protonic gate with an
electron doping concentration up to 3.8 * 10^21 cm^-3. We observed
non-monotonic evolutions in both coercivity and anomalous Hall resistivity.
Under increased electron doping, the coercivities and anomalous Hall effects
(AHEs) vanished, indicating a doping-induced magnetic phase transition. This
occurred up to room temperature. DFT calculations showed the formation of an
antiferromagnetic (AFM) phase caused by the intercalation of protons which
induced significant electron doping in the Cr1.2Te2. The tunability of the
magnetic properties and phase in room temperature magnetic vdW Cr1.2Te2 is a
significant step towards practical spintronic devices.Comment: 18 pages, 4 figure