Ferrimagnetism in Cr-substituted Mn_4–xCr_xAl₁₁

We report on the flux growth, x-ray diffraction, magnetic measurements, and density functional theory calculations of the new mixed-site compound Mn_4–xCr_xAl₁₁ (x = 1.74). This compound is isostructural with binaries Mn₄Al₁₁ and Cr₄Al₁₁, and experiences site-mixing at both transition metal sites, although at different Mn:Cr ratios: 0.64:0.36 at one site and 0.49:0.51 at the other site. Magnetic measurements show that it is a ferrimagnet unlike the Mn₄Al₁₁ binary displaying one-dimensional magnetic character. The DFT calculations indicate that Mn_2.26Cr_1.74Al₁₁ is possibly a half-metal.