  We present the studies of magnetic properties of Ge/1-x/Cr/x/Te diluted
magnetic semiconductor with changeable chemical composition 0.016 \leq x \leq
0.061. A spin-glass state (at T \leq 35 K) for x = 0.016 and 0.025 and a
ferromagnetic phase (at T < 60 K) for x \geq 0.030 are observed. The long range
carrier-mediated magnetic interactions are found to be responsible for the
observed magnetic ordering for x < 0.045, while for x \geq 0.045 the spinodal
decomposition of Cr ions leads to a maximum and decrease of the Curie
temperature, TC, with increasing x. The calculations based on spin waves model
are able to reproduce the observed magnetic properties at a homogeneous limit
of Cr alloying, e.g. x < 0.04, and prove that carrier mediated
Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction is responsible for the
observed magnetic states. The value of the Cr-hole exchange integral, Jpd,
estimated via fitting of the experimental results with the theoretical model,
is in the limits 0.77...0.88 eV.
