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/

Zendy Plus

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

Zendy Tools

Zendy Open

We consider theoretically the paramagnetic phases of EuTiO3 that representconfigurations created by two sets of microscopic degrees of freedom (m-DOF):positional symmetry breaking due to octahedral rotations and magnetic symmetrybreaking due to spin disorder. The effect of these sets of m-DOFs on theelectronic structure and properties of the para phases is assessed byconsidering sufficiently large (super) cells with the required nominal globalaverage symmetry, allowing, however, the local positional and magneticsymmetries to be lowered. We find that tendencies for local symmetry breakingcan be monitored by following total energy lowering in mean-field like densityfunctional theory, without recourse for strong correlation effects. While mostnominally cubic ABO3 perovskites are known for their symmetry breaking due tothe B-atom sublattice, the case of f-electron magnetism in EuTiO3 is associatedwith A- sublattice symmetry breaking and its coupling to structuraldistortions. We find that (i) paramagnetic cubic EuTiO3 has an intrinsictendency for both magnetic and positional symmetry breaking, while paramagnetictetragonal EuTiO3 has only magnetic symmetry lowering and no noticeablepositional symmetry lowering with respect to low-temperature antiferromagnetictetragonal phase. (ii) Properly modeled paramagnetic tetragonal and cubicEuTiO3 have a nonzero local magnetic moment on each Eu ion, consistent with theexperimental observations of local magnetism in the para phases of EuTiO3significantly above the N\'eel temperature. Interestingly, (iii) the localpositional distortion modes in the short-range ordered para phases areinherited from the long-range ordered low-temperature antiferromagnetic groundstate phase.

Local positional and spin symmetry breaking as a source of magnetism and insulation in paramagnetic EuTiO3