| Autor: |
Klepov VV; Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States., Pace KA; Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States., Berseneva AA; Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States., Felder JB, Calder S, Morrison G; Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States., Zhang Q, Kirkham MJ, Parker DS, Zur Loye HC; Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States. |
| Abstrakt: |
Geometrically frustrated systems play an important role in studying new physical phenomena and unconventional thermodynamics. Charge ordered defect pyrochlores AM 2+ M 3+ F 6 offer a convenient platform for probing the interplay between electron distribution over M 2+ and M 3+ sites and structural distortions; however, they are limited to compounds with M 2+/3+ = V, Fe, Ni, and Cu due to difficulties in the simultaneous stabilization of other 3d elements in the +2 and +3 oxidation states. Herein, we employ Cl - anions under hydrothermal conditions for the mild reduction of Mn 2 O 3 in concentrated HF to obtain the CsMn 2+ Mn 3+ F 6 composition as a phase pure sample and study its properties. The magnetism of CsMn 2 F 6 was characterized by measuring the magnetic susceptibility and isothermal magnetization data, and a magnetic transition to a canted antiferromagnet state was found at 24.1 K. We determined the magnetic structure of CsMn 2 F 6 using powder neutron diffraction, which revealed successive long-range ordering of the Mn 2+ and Mn 3+ sites that is accompanied by a second transition. The role and strength of magnetic exchange interactions were characterized using DFT calculations. |
