93 research outputs found
Towards diluted magnetism in TaAs
Magnetism in Weyl semimetals is desired to investigate the interaction
between the magnetic moments and Weyl fermions, e.g. to explore anomalous
quantum Hall phenomena. Here we demonstrate that proton irradiation is an
effective tool to induce ferromagnetism in the Weyl semimetal TaAs. The
intrinsic magnetism is observed with a transition temperature above room
temperature. The magnetic moments from d states are found to be localized
around Ta atoms. Further, the first-principles calculations indicate that the d
states localized on the nearest-neighbor Ta atoms of As vacancy sites are
responsible for the observed magnetic moments and the long-ranged magnetic
order. The results show the feasibility of inducing ferromagnetism in Weyl
semimetals so that they may facilitate the applications of this material in
spintronics.Comment: 20 pages, 6 figure
On Curie temperature of B20-MnSi films
B20-type MnSi is the prototype magnetic skyrmion material. Thin films of MnSi
show a higher Curie temperature than their bulk counterpart. However, it is not
yet clear what mechanism leads to the increase of the Curie temperature. In
this work, we grow MnSi films on Si(100) and Si(111) substrates with a broad
variation in their structures. By controlling the Mn thickness and annealing
parameters, the pure MnSi phase of polycrystalline and textured nature as well
as the mixed phase of MnSi and MnSi1.7 are obtained. Surprisingly, all these
MnSi films show an increased Curie temperature of up to around 43 K. The Curie
temperature is likely independent of the structural parameters within our
accessibility including the film thickness above a threshold, strain, cell
volume and the mixture with MnSi1.7. However, a pronounced phonon softening is
observed for all samples, which can tentatively be attributed to slight Mn
excess from stoichiometry, leading to the increased Curie temperature.Comment: 20 pages, 6 figure
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On Curie temperature of B20-MnSi films
B20-type MnSi is the prototype magnetic skyrmion material. Thin films of MnSi show a higher Curie temperature than their bulk counterpart. However, it is not yet clear what mechanism leads to the increase of the Curie temperature. In this work, we grow MnSi films on Si(100) and Si(111) substrates with a broad variation in their structures. By controlling the Mn thickness and annealing parameters, the pure MnSi phase of polycrystalline and textured nature as well as the mixed phase of MnSi and MnSi1.7 are obtained. Surprisingly, all these MnSi films show an increased Curie temperature of up to around 43 K. The Curie temperature is likely independent of the structural parameters within our accessibility including the film thickness above a threshold, strain, cell volume and the mixture with MnSi1.7. However, a pronounced phonon softening is observed for all samples, which can tentatively be attributed to slight Mn excess from stoichiometry, leading to the increased Curie temperature
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