Related Experiment Videos
beta-Y(2)Si(2)O(7), a new thortveitite-type compound, determined at 100 and 280 K.
G ünther J Redhammer G1, Georg Roth
1Institute of Crystallography, Jägerstrasse 17/19, D-52056 Aachen, Germany. guenther.redhammer@aon.at
Summary
A new diyttrium heptaoxodisilicate (Y2Si2O7) structure, isotypic with thortveitite, was synthesized. This crystal structure exhibits a centrosymmetric space group C2/m at low temperatures.
Area of Science:
- Solid-state chemistry
- Crystallography
- Materials science
Background:
- Yttrium silicates are important materials with diverse applications.
- Understanding the crystal structure of Y2Si2O7 is crucial for its properties.
Purpose of the Study:
- To synthesize and characterize a new form of Y2Si2O7.
- To determine its crystal structure and compare it with known silicate structures.
Main Methods:
- Synthesis of Y2Si2O7 via solid-state reaction.
- X-ray diffraction (XRD) for crystal structure determination at 100 K and 280 K.
- Rietveld refinement for structural analysis.
Main Results:
- A new Y2Si2O7 polymorph was synthesized, isotypic with thortveitite (Sc2Si2O7).
- The crystal structure crystallizes in the centrosymmetric space group C2/m.
- Y3+ cations occupy distorted octahedral sites, and SiO4 tetrahedra are regular.
- Small structural changes were observed upon cooling, with a decrease in the anisotropic displacement of the bridging oxygen atom.
Conclusions:
- The C2/m structure model for Y2Si2O7 is favored over the non-centrosymmetric C2 space group.
- The study provides detailed structural insights into this new Y2Si2O7 polymorph.