  EuCd$_2$As$_2$ is an antiferromagnetic semimetal, that can host non-trivial
topological properties, depending upon its magnetic state and excitations.
Here, we report the synthesis and characterization of
Eu(Cd$_{1-x}$Ag$_x$)$_2$As$_2$ and Eu$_{1-y}$Na$_y$Cd$_2$As$_2$, and study the
evolution and nature of magnetic order with doping. Temperature-substitution
phase diagrams are constructed from the electrical resistance and magnetic
susceptibility data. We observe a splitting of the magnetic transition into two
different transitions, and the gradual increase in one of the transition
temperatures with Ag- and Na-substitution. The other transition remains more or
less independent of doping. We further show that a magnetic state with a net
ferromagnetic moment is stabilized by both Ag and Na doping and this can be
explained by considering the changes in band filling due to substitution as
suggested by density functional theory (DFT) calculations. We thus show that
chemical substitution and the subsequent changes in band filling could be a
pathway to tune the magnetic ground state and to stabilize a ferromagnetic
phase in EuCd$_2$As$_2$.
