Single-crystal X-ray diffraction and electron-microscopy study of multiple-twinned Sr(3)(Ru0.336,Pt0.664)CuO(6)

Area of Science:

• Crystallography
• Materials Science
• Solid-State Chemistry

Background:

• The study investigates the crystal structure of strontium ruthenium platinum copper oxide, Sr3(Ru0.336,Pt0.664)CuO6.
• Understanding the atomic arrangement and bonding is crucial for predicting material properties.

Purpose of the Study:

• To determine the precise crystal structure of Sr3(Ru0.336,Pt0.664)CuO6 using single-crystal X-ray diffraction.
• To investigate the coordination environments of the metal cations (Sr, Ru, Pt, Cu) and their arrangement within the unit cell.
• To analyze the twinning behavior and its relationship to the crystal structure.

Main Methods:

• Single-crystal X-ray diffraction was employed to elucidate the crystal structure and lattice parameters.
• Electron microscopy was used to confirm the structural findings and analyze domain structures.
• Analysis of coordination polyhedra and bonding environments for each atom.

Main Results:

• Sr3(Ru0.336,Pt0.664)CuO6 crystallizes in a monoclinic structure (space group R12/c) with pseudo-trigonal symmetry.
• The crystal was a multiple twin, with twin laws involving rhombohedral and trigonal elements.
• [(Ru,Pt)O6] octahedra connect to Cu-O polyhedra, forming chains along the c-axis, with Sr2+ ions situated between these chains.
• Coordination environments were characterized: pseudo-octahedral for (Ru,Pt), distorted trigonal prism for Cu, and eight-fold for Sr.
• Electron microscopy corroborated the X-ray diffraction results, and the observed domain structures were consistent with the established twin model.
• No evidence of Pt/Ru ordering was detected.

Conclusions:

• The crystal structure of Sr3(Ru0.336,Pt0.664)CuO6 is definitively determined, revealing a complex monoclinic arrangement with pseudo-trigonal characteristics.
• The twinning phenomenon is well-described and understood within the context of the crystal structure.
• The absence of Pt/Ru ordering suggests a random distribution of these elements within the crystal structure, impacting potential physical properties.