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

Pb 5 Al 3 F 19  undergoes three first-order phase transitions; on cooling from phase I (4/ m ) to phase II (2/ m ) at 365 K, from phase II to phase III (4/ m ) at 305 K, and from phase III to phase IV (4 mm ) at 120 K. The lengths of the  a - and  c -axes undergo continuous change at the highest temperature phase transition as the  β -angle increases from 90[unk] below 365 K; no difference is detectable between the lengths of the  a - and  b -axes in monoclinic phase II, within an accuracy of 0.007 Å. The  β -angle temperature dependence follows a power law with exponent that does not differ significantly from 1/2. At the 305 K first-order phase transition, the  β -angle abruptly changes from its maximum value of 90.41° in phase II to 90[unk] in tetragonal phase III; the  a - and  c -axes, however, maintain their continuous change in length through this transition. The 120 K first-order phase transition is characterized by an abrupt 0.77% decrease in the length of the normalized  a -axis, and an equally abrupt 1.89% increase in the  c -axis length, on cooling from phase III to phase IV. The  a - and  c -axes in all four phases are characterized by linear thermal coefficients, with magnitudes presented below. The normalized  a -axis lengths in phases I, II and III extrapolated to 0 K differ by less than 0.021 Å from 14.174 Å, the corresponding  c -axis lengths at 0 K differ by less than 0.004 Å from 7.194 Å. The normalized unit cell volume thermal dependence of phases I, II and III is linear and continuous between 400 and 120 K but undergoes a discontinuity of 0.40% at the transition from phase III to phase IV.

Thermal dependence of the Pb 5 Al 3 F 19 lattice parameters in phases I–IV