English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

In the metallic magnet Nb$_{1-y}$Fe$_{2+y}$, the low temperature threshold offerromagnetism can be investigated by varying the Fe excess $y$ within a narrowhomogeneity range. We use elastic neutron scattering to track the evolution ofmagnetic order from Fe-rich, ferromagnetic Nb$_{0.981}$Fe$_{2.019}$ toapproximately stoichiometric NbFe$_2$, in which we can, for the first time,characterise a long-wavelength spin density wave state burying a ferromagneticquantum critical point. The associated ordering wavevector $\mathbf{q}_{\rmSDW}=$(0,0,$l_{\rm SDW}$) is found to depend significantly on $y$ and $T$,staying finite but decreasing as the ferromagnetic state is approached. Thephase diagram follows a two order-parameter Landau theory, for which all thecoefficients can now be determined. Our findings suggest that the emergence ofSDW order cannot be attributed to band structure effects alone. They indicate acommon microscopic origin of both types of magnetic order and provide strongconstraints on related theoretical scenarios based on, e.g., quantum order bydisorder.

Ultra-small moment incommensurate spin density wave order masking a ferromagnetic quantum critical point in NbFe$_2$