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(Cr2Ti)AlC2 is a newly discovered MAX phase with ordered occupations of Ti and Cr atoms on M sites. The Cr-containing MAX phase is expected showing magnetic property, which provides functional applications in spintronics and as self-monitoring smart coating. The magnetic states of (Cr2Ti)AlC2 are predicted by GGA and GGA + U methods and compared to those of Cr2AlC. The ground states are predicted as FM or AFM-XX configurations depending on the calculation methods. Analysis of the electronic structure shows that the magnetic moments mainly originate from the net spins of Cr 3d valence electrons, whereas the contribution of other atoms is negligible. The calculated magnetic moments of Cr atoms in (Cr2Ti)AlC2 are higher than those in Cr2AlC due to the larger distance between the out-plane Cr atoms separated by the intercalated nonmagnetic Ti-C slab. This work provides an insight on tailoring magnetic properties of MAX phases by modifying the crystal structure. [ABSTRACT FROM AUTHOR]

Two new MAX compounds, ( Cr2/3 Ti1/3)3 AlC2 and ( Cr5/8 Ti3/8)4 AlC3, were successfully synthesized by hot-pressing elemental powders at 1500°C for 1 h under 30 MPa in a flowing argon atmosphere. Their crystal structures were indentified and characterized by X-ray diffraction and transmission electron microscopy analysis. ( Cr2/3 Ti1/3)3 AlC2 and ( Cr5/8 Ti3/8)4 AlC3 have the same crystal structures with the well-characterized Ti3 AlC2 and Ti4 AlN3, respectively. [ABSTRACT FROM AUTHOR]