Structure solution of the new titanate Li4Ti8Ni3O21 using precession electron diffraction

Area of Science:

• Materials Science
• Crystallography
• Solid-State Chemistry

Background:

• Spinel structures are common in lithium-titanium-nickel oxides.
• Synthesis of novel crystalline phases can lead to new material properties.

Purpose of the Study:

• To synthesize a Li[Ti(1.5)Ni(0.5)]O(4) sample.
• To characterize the crystalline phases present in the synthesized material.
• To determine the crystal structure of any novel phases.

Main Methods:

• Sample synthesis with a target Li[Ti(1.5)Ni(0.5)]O(4) stoichiometry.
• X-ray diffraction (XRD) and precession electron diffraction for structural analysis.
• Structure solution using direct methods and refinement with synchrotron powder diffraction data.

Main Results:

• The synthesized powder exhibited a multiphase nature, with spinel as a minor phase.
• A new trigonal phase was identified as the main component.
• The trigonal phase structure was solved in space group P3c1, with lattice parameters a = 5.05910(1) Å and c = 32.5371(1) Å.
• The refined stoichiometry for the new phase is Li(4)Ti(8)Ni(3)O(21).

Conclusions:

• A novel trigonal phase of lithium titanium nickel oxide was successfully synthesized and characterized.
• The crystal structure of this new phase was determined, revealing hexagonal layers of edge-sharing octahedra.
• The findings expand the known structural landscape of lithium titanium nickel oxide materials.