Three cubic phases intergrown in a birefringent andradite-grossular garnet and their implications

Two isotropic grossular (ideally Ca3Al2Si3O12) samples from (1) Canada and (2) Tanzania, three optically anisotropic grossular samples (3, 4, 5) from Mexico, and one (6) anisotropic sample from Italy were studied. The crystal structure of the six samples was refined in the cubic space group Ia3¯d, using monochromatic synchrotron high-resolution powder X-ray diffraction (HRPXRD) data and the Rietveld method. The compositions of the samples were obtained from electron microprobe analyses (EPMA). The HRPXRD traces show a single cubic phase for two isotropic samples, whereas the four anisotropic samples contain two different cubic phases that were also resolved using X-ray elemental line scans, backscattered electron (BSE) images, and elemental maps. Structural mismatch from two cubic phases intergrown in the birefringent samples gives rise to strain-induced optical anisotropy. Considering the garnet general formula, [8]X3[6]Y2[4]Z3[4]O12, the results of this study show that with increasing unit-cell parameter, the Y-O distance increases linearly and rather steeply, the average <X-O> distance increases just slightly in response to substitution mainly on the Y site, while the Z-O distance remains nearly constant. The X and Z sites in grossular contain Ca and Si atoms, respectively; both sites show insignificant substitutions by other atoms, which is supported by a constant Z-O distance and only a slight increase in the average <X-O> distance. The main cation exchange is realized in the Y site, where Fe3+ (ionic radius = 0.645 Å) replaces Al3+ (ionic radius = 0.545 Å), so the Y-O distance increases the most.

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MODULATED FRINGE PATTERN PHOTOBLEACHING APPLIED TO LIPID-WATER CUBIC PHASES : STRUCTURAL INFORMATION

Le Journal de Physique Colloques ◽

10.1051/jphyscol:1990709 ◽

1990 ◽

Vol 51 (C7) ◽

pp. C7-105-C7-108

Author(s):

S. CRIBIER ◽

L. BOURDIEU ◽

R. VARGAS ◽

A. GULIK ◽

V. LUZZATI

Keyword(s):

Fringe Pattern ◽

Structural Information ◽

Cubic Phases

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X-RAY STUDY OF CUBIC PHASES IN TERNARY SYSTEMS OF SURFACTANT DDAB, WATER AND OIL

Le Journal de Physique Colloques ◽

10.1051/jphyscol:1990703 ◽

1990 ◽

Vol 51 (C7) ◽

pp. C7-25-C7-34 ◽

Cited By ~ 3

Author(s):

P. BAROIS ◽

D. EIDAM ◽

S. T. HYDE

Keyword(s):

Ternary Systems ◽

X Ray ◽

Cubic Phases

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3D Crystallization and Structural Studies of Integral Membrane Proteins in Lipidic Cubic phases

Acta Crystallographica Section A Foundations of Crystallography ◽

10.1107/s0108767300022418 ◽

2000 ◽

Vol 56 (s1) ◽

pp. s83-s83

Author(s):

P. Nollert ◽

M. L. Chiu ◽

M. C. Loewen ◽

A. Royant ◽

H. Behrhali ◽

...

Keyword(s):

Membrane Proteins ◽

Integral Membrane Proteins ◽

Structural Studies ◽

Cubic Phases

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Diffusionless transformation of soft cubic superstructure from amorphous to simple cubic and body-centered cubic phases

Nature Communications ◽

10.1038/s41467-021-23631-w ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Jie Liu ◽

Wenzhe Liu ◽

Bo Guan ◽

Bo Wang ◽

Lei Shi ◽

...

Keyword(s):

Liquid Crystals ◽

X Ray Diffraction ◽

Photonic Materials ◽

Simple Cubic ◽

Cubic Phases ◽

Transmission Electron ◽

Phase Liquid ◽

Blue Phase ◽

Blue Phases ◽

Temperature Window

AbstractIn a narrow temperature window in going from the isotropic to highly chiral orders, cholesteric liquid crystals exhibit so-called blue phases, consisting of different morphologies of long, space-filling double twisted cylinders. Those of cubic spatial symmetry have attracted considerable attention in recent years as templates for soft photonic materials. The latter often requires the creation of monodomains of predefined orientation and size, but their engineering is complicated by a lack of comprehensive understanding of how blue phases nucleate and transform into each other at a submicrometer length scale. In this work, we accomplish this by intercepting nucleation processes at intermediate stages with fast cross-linking of a stabilizing polymer matrix. We reveal using transmission electron microscopy, synchrotron small-angle X-ray diffraction, and angle-resolved microspectroscopy that the grid of double-twisted cylinders undergoes highly coordinated, diffusionless transformations. In light of our findings, the implementation of several applications is discussed, such as temperature-switchable QR codes, micro-area lasing, and fabrication of blue phase liquid crystals with large domain sizes.

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