  The magnetic properties of antiferromagnetic (AFM) EuTe epitaxial layers and
short period EuTe/PbTe superlattices (SLs), grown by molecular beam epitaxy on
(111) BaF$_2$ substrates, were studied by magnetization and neutron diffraction
measurements. Considerable changes of the N\'eel temperature as a function of
the EuTe layer thickness as well as of the strain state were found. A mean
field model, taking into account the variation of the exchange constants with
the strain-induced lattice distortions, and the nearest neighbor environment of
a Eu atoms, was developed to explain the observed $T_{\text N}$ changes in wide
range of samples. Pronounced interlayer magnetic correlations have been
revealed by neutron diffraction in EuTe/PbTe SLs with PbTe spacer thickness up
to 60 \AA. The observed diffraction spectra were analyzed, in a kinematical
approximation, assuming partial interlayer correlations characterized by an
appropriate correlation parameter. The formation of interlayer correlations
between the AFM EuTe layers across the nonmagnetic PbTe spacer was explained
within a framework of a tight-binding model. In this model, the interlayer
coupling stems from the dependence of the total electronic energy of the
EuTe/PbTe SL on the spin configurations in adjacent EuTe layers. The influence
of the EuTe and PbTe layer thickness fluctuations, inherent in the epitaxial
growth process, on magnetic properties and interlayer coupling is discussed.
