  In the present work, we analyse the effects of an external magnetic field on
the chiral critical temperature $T_c$ of strongly interacting matter. In doing
this, we can characterize the magnetic properties of the quantum chromodynamics
(QCD) strong interacting matter, the quark-gluon plasma (QGP). We investigate
this in the framework of the SU(3) Polyakov linear sigma-model (PLSM). To this
end, we implement two approaches representing two systems, in which the
Polyakov-loop potential added to PLMS either renormalized or non-normalized.
The effects of Landau quantization on the strongly interacting matter is
conjectures to reduce the electromagnetic interactions between quarks. In this
case, the color interactions will be dominant and increasing, which - in turn -
can be achieved by increasing of the Polyakov-loop fields. Obviously, each of
them equips us with a different understanding about the critical temperature
under the effect of an external magnetic field. In both systems, we obtain a
paramagnetic response. In one system, we find that $T_c$ increases with
increasing the magnetic field. In the other one, $T_c$ significantly decreases
with increasing the magnetic field.
