  The cubic Heusler alloy Ru$_{2-x}$Mn$_{1+x}$Al is grown in thin film form on
MgO and MgAl$_2$O$_4$ substrates. It is a highly spin-polarised ferrimagnetic
metal, with weak magnetocrystalline anisotropy. Although structurally and
chemically similar to $\text{Mn}_2\text{Ru}_x\text{Ga}$, it does not exhibit
ferrimagnetic compensation, or large magneto galvanic effects. The differences
are attributed to a combination of atomic order and the hybridisation with the
group 13 element Al or Ga. The spin polarisation is around 50 to 60 %. There is
a gap in the density of states just above the Fermi level in fully ordered
compounds.
