In-plane magnetic structure and exchange interactions in the high-temperature antiferromagnet Cr2Al

The ordered tetragonal intermetallic Cr2Al forms the same structure type as Mn2Au, and the latter has been heavily investigated for its potential in antiferromagnetic spintronics due to its degenerate in-plane Néel vector. We present the single-crystal flux growth of Cr2Al and orientation-dependent magnetic properties. Powder neutron diffraction of Cr2Al and first-principles simulations reveal that the magnetic ordering is likely in-plane and therefore identical to Mn2Au, providing a second material candidate in the MoSi2 structure type to evaluate the fundamental interactions that govern spintronic effects. The single ordering transition seen in thermal analysis and resistivity indicates that canting of the moments along the c axis is unlikely. Magnetometry, resistivity, and differential scanning calorimetry measurements confirm the Néel temperature to be 634±2 K. First-principles simulations indicate that the system has a small density of states at the Fermi energy and confirm the lowest-energy magnetic ground-state ordering, while Monte Carlo simulations match the experimental Néel temperature.