Nanostructured Mn—Al, Mn—Al—C permanent magnets are disclosed. The magnets have high coercivities (about 4.8 kOe and 5.2 kOe) and high magnetization values. An intennetallic composition includes a ternary transition metal modified manganese aluminum alloy Mn—Al—Fe, Mn—Al—Ni, or Mn—Al—Co having at least about 80% of a magnetic τ phase and permanent magnetic properties. The alloy may have a saturation magnetization value of at least 96 emu/g with approximately 5% ternary transition metal replacing Al. The alloy may also have a saturation magnetization value of at least 105 emu/g with 10% ternary transition metal replacing Al.