Beschreibung:
<jats:title>Abstract</jats:title><jats:p>The antiferromagnetic phase transition of octahedrally coordinated (Cd. Mn)S single crystals with Mn concentrations 0.8 ≦ <jats:italic>x</jats:italic>Mn ≦ 1 is studied by EPR measurements in the temperature range 80 to 550 K. The width of the Mn<jats:sup>2+</jats:sup> EPR line is found to increase with decreasing temperature nearly proportional to (<jats:italic>T</jats:italic> ‐ <jats:italic>T</jats:italic><jats:sub>N</jats:sub>)s<jats:sup>−1</jats:sup> due to a corresponding decrease of the spin‐spin relaxation time. The Néel temperature <jats:italic>T</jats:italic><jats:sub>N</jats:sub> for the transition from the paramagnetic into the (disordered) antiferromagnetic phase being determined from the linewidth divergence decreases strongly with decreasing <jats:italic>x</jats:italic>Mn. The results are discussed in connection with actual EPR investigations of (Cd, Mn) and (Zn, Mn) chalcogenide mixed crystals with zincblende/wurtzite structure for lower Mn concentrations. The EPR signal below <jats:italic>T</jats:italic><jats:sub>N</jats:sub> being observed in the case of polycrystalline thin films or powder samples is ascribed to surface near regions of the microcrystals.</jats:p>