Two new MAX compounds, (Cr2/3Ti1/3)3AlC2 and (Cr5/8Ti3/8)4AlC3, 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. (Cr2/3Ti1/3)3AlC2 and (Cr5/8Ti3/8)4AlC3 have the same crystal structures with the well‐characterized Ti3AlC2 and Ti4AlN3, respectively.

FDG PET/CT was performed in a 20-year-old woman to find the underlying cause of hemophagocytic lymphohistiocytosis. The images revealed hypermetabolic activity in multiple lymph nodes and in the spleen. Lymphoma was suspected. However, the pathology of bone marrow, lymph nodes, and the spleen demonstrated chronic active Epstein-Barr virus–associated T-cell lymphoproliferative disorders.

(Cr 2 Ti)AlC 2 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 (Cr 2 Ti)AlC 2 are predicted by GGA and GGA + U methods and compared to those of Cr 2 AlC. 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 (Cr 2 Ti)AlC 2 are higher than those in Cr 2 AlC 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.