Valence states key to understanding the Cr12-xTe16 compound

April 2, 2020
Valence states key to understanding the Cr12-xTe16 compound
(Left) Neutron diffraction patterns in the (HHL) scattering plane at T = 5K with arrows marking the peaks showing magnetic contributions. (Right) Crystal structure illustrating the isolated Cr2/C3 magnetic layers. Note that the Cr4 position is partially occupied.

Scientific Achievement

The magnetic structure of Cr9.35Te16 was solved, showing that of the four Cr-ions  in the unit cell, two (Cr2/Cr3) with valence Cr3+ have ferromagnetically aligned moments, and two (Cr1/Cr4) with valence Cr2+ show no ordered moment.

Significance and Impact

Physical properties of the Cr-Te system can be tuned by varying the Cr-content, and here have led to a new and unique two-dimensional material with magnetism confined to the Cr2/Cr3 layers.

Research Details

  • The magnetic structure was determined by neutron diffraction.
  • The Cr valences were determined by XANES (x-ray absorption near edge structure).

“Structure, chromium vacancies, and magnetism in a Cr12−xTe16 compound,”
Guixin Cao1, Qiang Zhang1,2, Matthias Frontzek2, Weiwei Xie3, Dongliang Gong1, George E. Sterbinsky4, and Rongying Jin1,
Physical Review Materials, 3, 125001 (2019).