Synthesis of a d1-titanium fluoride kagome lattice antiferromagnet

Ningxin Jiang; Arun Ramanathan; John Bacsa; Henry S La Pierre

doi:10.1038/s41557-020-0490-8

Synthesis of a d¹-titanium fluoride kagome lattice antiferromagnet

Nat Chem. 2020 Aug;12(8):691-696. doi: 10.1038/s41557-020-0490-8. Epub 2020 Jun 29.

Authors

Ningxin Jiang¹, Arun Ramanathan¹, John Bacsa¹, Henry S La Pierre^{2

3}

Affiliations

¹ School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA, USA.
² School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA, USA. hsl@gatech.edu.
³ Nuclear and Radiological Engineering Program, School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, USA. hsl@gatech.edu.

PMID: 32601408
DOI: 10.1038/s41557-020-0490-8

Abstract

The kagome lattice, composed of a planar array of corner-sharing triangles, is one of the most geometrically frustrated lattices. The realization of a spin S = 1/2 kagome lattice antiferromagnet is of particular interest because it may host an exotic form of matter, a quantum spin liquid state, which shows long-range entanglement and no magnetic ordering down to 0 K. A few S = 1/2 kagome lattice antiferromagnets exist, typically based on Cu²⁺, d⁹ compounds, though they feature structural imperfections. Herein, we present the synthesis of (CH₃NH₃)₂NaTi₃F₁₂, which comprises an S = 1/2 kagome layer that exhibits only one crystallographically distinct Ti³⁺, d¹ site, and one type of bridging fluoride. A static positional disorder is proposed for the interlayer CH₃NH₃⁺. No structural phase transitions were observed from 1.8 K to 523 K. Despite its spin-freezing behaviour, other features-including its negative Curie-Weiss temperature and a lack of long-range ordering-imply that this compound is a highly frustrated magnet with unusual magnetic phase behaviours.