Monoclinic-orthorhombic first-order phase transition in K<inf>2</inf>ZnSi<inf>5</inf>O<inf>12</inf>leucite analogue; Transition mechanism and spontaneous strain analysis

BELL, AMT, CLEGG, Francis and HENDERSON, CMB (2021). Monoclinic-orthorhombic first-order phase transition in K<inf>2</inf>ZnSi<inf>5</inf>O<inf>12</inf>leucite analogue; Transition mechanism and spontaneous strain analysis. Mineralogical Magazine.

Preview	PDF Bell-MonoclinicOrthorhombicFirstOrderPhase(AM).pdf - Accepted Version Creative Commons Attribution Non-commercial No Derivatives. Download (349kB) | Preview
Preview	Image (JPEG) (Figure 1) Bell-Monoclinic(Fig1).jpg - Supplemental Material Creative Commons Attribution Non-commercial No Derivatives. Download (2kB) | Preview
Preview	Image (JPEG) (Figure 2) Bell-Monoclinic(Fig2).jpg - Supplemental Material Creative Commons Attribution Non-commercial No Derivatives. Download (2kB) | Preview
Preview	Image (JPEG) (Figure 3) Bell-Monoclinic(Fig3).jpg - Supplemental Material Creative Commons Attribution Non-commercial No Derivatives. Download (2kB) | Preview
Preview	Image (JPEG) (Figure 4) Bell-Monoclinic(Fig4).jpg - Supplemental Material Creative Commons Attribution Non-commercial No Derivatives. Download (5kB) | Preview
Preview	Image (JPEG) (Figure 5) Bell-Monoclinic(Fig5).jpg - Supplemental Material Creative Commons Attribution Non-commercial No Derivatives. Download (2kB) | Preview
Preview	Image (JPEG) (Figure 6) Bell-Monoclinic(Fig6).jpg - Supplemental Material Creative Commons Attribution Non-commercial No Derivatives. Download (2kB) | Preview
Preview	Image (JPEG) (Figure 7) Bell-Monoclinic(Fig7).jpg - Supplemental Material Creative Commons Attribution Non-commercial No Derivatives. Download (2kB) | Preview
Preview	Image (JPEG) (Figure 8) Bell-Monoclinic(Fig8).jpg - Supplemental Material Creative Commons Attribution Non-commercial No Derivatives. Download (2kB) | Preview

Abstract

Hydrothermally synthesised K2ZnSi5O12 has a polymerized framework structure with the same topology as leucite (KAlSi2O6, tetragonal I41/a), which has two tetrahedrally coordinated Al3+ cations replaced by Zn2+ and Si4+. At 293K it has a cation-ordered framework P21/c monoclinic structure with lattice parameters a = 13.1773(2)A, b = 13.6106(2) A, c = 13.0248(2)A, = 91.6981(9). This structure is isostructural with K2MgSi5O12, the first cation-ordered leucite analogue characterised. With increasing temperature, the P21/c structure transforms reversibly to cation-ordered framework orthorhombic Pbca. This transition takes place over the temperature range 848-863K where both phases coexist; there is an 1.2% increase in unit cell volume between 843K (P21/c) and 868K (Pbca), characteristic of a first-order, displacive, ferroelastic phase transition. Spontaneous strain analysis defines the symmetry- and non-symmetry related changes and shows that the mechanism is weakly first order; the two-phase region is consistent with the mechanism being a strain-related martensitic transition.

Item Type:	Article
Uncontrolled Keywords:	0306 Physical Chemistry (incl. Structural); 0403 Geology; Geochemistry & Geophysics
Identification Number:	https://doi.org/10.1180/mgm.2021.67
SWORD Depositor:	Symplectic Elements
Depositing User:	Symplectic Elements
Date Deposited:	21 Sep 2021 14:47
Last Modified:	26 Feb 2022 01:18
URI:	https://shura.shu.ac.uk/id/eprint/29084

Actions (login required)

View Item

Downloads

Publication Metrics