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

Elastic and structural behavior of a natural cubic analcime (space group: Ia3 . d) from Sardinia (Italy) was investigated at high pressure by in situ single-crystal X-ray diffraction. A first-order phase transition is observed in the pressure range between 0.91(5) and 1.08(5) GPa. Unit-cell constants and reflection conditions confirm that the space group of the HP-polymorph is P1̄. No further phasetransition has been observed at least up to 7.14 GPa. Fitting the volume data of the cubic polymorph with a second-order BM-EoS we obtain: V 0  = 2571.2(4) Å 3 , K T0  = 56(3) GPa, and K’ = 4 (fixed). For the triclinic polymorph, a third-order EoS gives: V 0  = 2607(9) Å 3 , K T0  = 19(2) GPa, and K’ = 6.8(7). Axial bulk moduli of the triclinic polymorph, calculated with a linearized BM-EoS, are: K T0 (a) = 29(2) GPa, with K’(a) = 4.9(6) and a 0  = 13.727(10) Å; K T0 (b) = 20(1) GPa, with K’(b) = 5.2(5), and b 0  = 13.751(15) Å; K T0 (c) = 11(1) GPa, with K’(c) = 12.6(6) and c 0  = 13.822(31) Å. The elastic behavior of the HP-polymorph appears to be strongly anisotropic, being K T0 (a):K T0 (b):K T0 (c) = 2.64:1.82:1.00. The relevant structural variations in response to the cubic → triclinic phase transition are due to tetrahedral tilting. The tetrahedral framework distortion gives rise to a change of the eight- and six-ring channels ellipticity and of the extra-framework topological configuration: it appears in fact that for the high-pressure triclinic polymorph the coordination number of some of the Na atoms is seven (2H 2 O + five framework O atoms) instead of six (2H 2 O + four framework O atoms).

Elastic behavior, phase transition, and pressure induced structural evolution of analcime