  In this paper, we investigate the thermodynamic properties of a set of
neutral Dirac particles in the presence of an electromagnetic field in contact
with a heat bath for the relativistic and non-relativistic cases. In order to
perform the calculations, the high-temperature limit is considered and the
Euler-MacLaurin formula is taking into account. Next, we explicitly determine
the behavior of the main thermodynamic functions of the canonical ensemble: the
Helmholtz free energy, the mean energy, the entropy, and the heat capacity. As
a result, we verified that the mean energy and the heat capacity for the
relativistic case are two times the values of the non-relativistic case, thus,
satisfying the so-called Dulong-Petit law. In addition, we also verified that
the Helmholtz free energy and the entropy in both cases increase as a function
of the electric field. Finally, we note that there exists no influence on the
thermodynamic functions due to the magnetic field.
