| Autor: |
Masachchi LW; Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States., Keerthisinghe N; Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States., Morrison G; 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., Smith MD; Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States., Zur Loye HC; Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States. |
| Abstrakt: |
Geometric magnetic frustration arises when the geometry of a structure prevents the simultaneous fulfillment of nearest-neighbor antiferromagnetic interactions and is commonly observed in lattices that exhibit a triangular topology, such as those found in the pyrochlore structure. Via a mild hydrothermal route, we have synthesized seven quaternary β-pyrochlore-related fluorides A x M 2+ x M 3+ (2- x ) F 6 (A = Cs and Rb; M 2+ = Co 2+ , Ni 2+ , and Zn 2+ ; and M 3+ = V 3+ and Fe 3+ ). Crystal structures and compositions were determined using a combination of single-crystal X-ray diffraction and energy-dispersive spectroscopy. After adjusting the reaction conditions, phase-pure products of A x M 2+ x M 3+ (2- x ) F 6 were obtained. The magnetic susceptibility and isothermal magnetization data for all seven compounds were collected to interpret the magnetic behavior, which ranged from paramagnetic to antiferromagnetic with and without a ferromagnetic component. We found that the magnetic behavior of the A x M 2+ x V 3+ (2- x ) F 6 pyrochlore structures strongly depends on the presence or absence of unpaired electrons on the M 2+ position. The titled pyrochlore compounds, with the exception of the Zn-analogue, can be considered frustrated materials, with frustration indices in the range of 6-13. |
