Cr4PtGa17: A Novel Ferromagnetic Half-Heusler Compound

January 4, 2022
Cr4PtGa17: A Novel Ferromagnetic Half-Heusler Compound
(Top Left) Half-Heusler compound crystal structure. (Bottom Left) The breathing pyrochlore lattice constructed by magnetic Cr atoms. (Right) Magnetic structure obtained from single crystal neutron diffraction with the in-plane magnetic moments noted as red vectors. Green, blue, and orange balls represent Cr, Pt, and Ga atoms, respectively.

Scientific Achievement

It is shown that the intermetallic compound Cr4PtGa17 is the first known material with a ferromagnetic breathing pyrochlore lattice and moreover shows a half-Heusler structure of type XYZ with the formula (PtGa2) (Cr4Ga14)Ga (X = PtGa2, Y = Cr4Ga14, Z = Ga).

Significance and Impact

The material Cr4PtGa17 is a prototype for a new family of half-Heusler compounds that can be tuned by varying the composition to exhibit various magnetic properties that may be useful for spintronics and other applications.

Research Details

  • Single crystal growth used the self-flux method, and the crystal was characterized by single-crystal X-ray diffraction and bulk magnetic characterization showing a transition to ferromagnetism at T = 61 K and an effective moment of 0.25mB per Cr atom.
  • Single crystal neutron diffraction determined the crystal structure and showed the magnetic Cr atoms form a breathing pyrochlore lattice.
  • Density functional theory calculations show the material is nearly half-metallic.

"Ferromagnetic Cr4PtGa17: A Half-Heusler-Type Compound with a Breathing Pyrochlore Lattice"

Xin Gui, Erxi Feng, Huibo Cao, and Robert J. Cava Journal of the American Chemical Society, 143, 14342-14351 (2021).