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

X-ray diffraction studies to ~90 GPa at room temperature show thatFe$_{2}$TiO$_{4}$ ferrous inverse spinel undergoes the following sequence ofstructural transitions : cubic (Fd3m) to tetragonal (I41/amd)toorthorhombic(Cmcm) to orthorhombic(Pmma),at the indicated onset transitionpressures. Within the Cmcm phase, site-specific spin crossover is initiated andinvolves only highly distorted octahedral sites constituting ~25% of all Felocations. This is manifest as a steeper volume decrease of dV/V0 ~ 3.5% beyond~40 GPa and an emergent diamagnetic component discerned in 57Fe M\"ossbauerspectroscopy at variable cryogenic temperatures. A subsequent Cmcm to PmmaFe/Ti disorder-order reconfiguration is facilitated at 6-fold coordinated(octahedral) sites. The rest of the high-spin Fe in 6-fold and 8-foldcoordinated sites (~75% abundance) in the Pmma phase exhibit average saturationinternal magnetic fields of H$_{hf}$ ~ 42 T to ~90 GPa, typical of spin-only(orbitally quenched) Fermi-contact values. By contrast average H$_{hf}$ ~ 20 Tvalues, signifying unquenched orbital moments, occur below the 40-45 GPaspin-crossover initiation regime in the Cmcm phase. Therefore site-specificspin crossover invokes a cooperative lattice response and polyhedraldistortions at the rest of the high-spin Fe sites, translating to 3d level(sub-band) changes and consequential orbital moment quenching. Near ~90 GPaFe$_{2}$TiO$_{4}$ is a partially spin-converted chemically ordered Pmmapost-spinel structure having a persistent charge gap of ~100 meV. Despitestructural symmetry changes, partial spin crossover and lattice compressibilityresulting in a ~33% total reduction in unit-cell volume and corresponding 3dbandwidth broadening, strong electron correlations persist at highdensification.

Site-specific spin crossover in Fe$_{2}$TiO$_{4}$ post-spinel under high pressures to near a megabar