  The binary manganese aluminium (MnAl) alloy with L$1_0$ crystal structure is
a promising rare earth element-free permanent magnetic material because of its
exceptional magnetic properties. However, experimentally synthesizing it in a
stable bulk form is extremely challenging. Here, an alternative method of
stabilizing the material is proposed and theoretically verified by partially
substituting Mn and Al sites with Fe and Ni and identifying its enhanced phase
stability, magnetic anisotropy, and coercivity from density functional theory
(DFT), machine learning (ML) crystal graph convolution neural network (CGCNN),
and micro-magnetic modeling. When considering a fixed ($50\%$)-Ni, the magnetic
anisotropy increases with the increasing Fe content but decreases the formation
energy. The calculated formation energies, elastic constants, and phonon
frequencies demonstrate that all the binary and quaternary compositions are
stable. Most importantly, the magnetic moment and magnetic anisotropy constants
in $50\%$-Fe substituted composition (equiatomic phase) increase significantly
compared to the MnAl. The predicted coercivity of the equiatomic phase is
larger than the parent compound calculated by combining DFT computed parameters
with micromagnetic simulations.
