| Autor: |
O'Donnell S; Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1877, United States.; National Renewable Energy Laboratory, Golden, Colorado 80401, United States., Mahatara S; National Renewable Energy Laboratory, Golden, Colorado 80401, United States., Lany S; National Renewable Energy Laboratory, Golden, Colorado 80401, United States., Bauers SR; National Renewable Energy Laboratory, Golden, Colorado 80401, United States., Smaha RW; National Renewable Energy Laboratory, Golden, Colorado 80401, United States., Neilson JR; Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1877, United States. |
| Abstrakt: |
We investigate the synthesis of antiperovskite "Mn 3 AlN" using the published synthesis procedure, as well as several new reaction pathways. In each case, only a combination of antiperovskite Mn 4 N and Mn 5 Al 8 or precursors is obtained. The identity of the obtained antiperovskite phase is unambiguously determined to be Mn 4 N via synchrotron powder X-ray diffraction (SPXRD), X-ray absorption spectroscopy (XAS), and magnetometry. The experimental results are further supported by thermochemical calculations informed by density functional theory (DFT), which find Mn 3 AlN to be metastable versus decomposition into Mn and AlN. The DFT-based calculations also predict an antiferromagnetic ground state for Mn 3 AlN. This directly contradicts the previously reported ferromagnetic behavior of "Mn 3 AlN". Instead, the observed magnetic behavior is consistent with ferrimagnetic Mn 4 N. We examine the data in the original publication and conclude that the compound reported to be Mn 3 AlN is in fact Mn 4 N. |
