On new ternary phases from Eu–Zn–T (T = Al and Ga) systems

Novel ternary phases EuZn2−xGa2+x, EuZn2−xAl2+x, Eu2Zn14.32Al2.68 and Eu3Zn17.68Al4.32 have been synthesized at 400 °C, and characterized by means of X-ray single crystal diffraction at room temperature and magnetic measurements down to 1.72 K. EuZn2−xAl2+x and EuZn2−xGa2+x compounds crystallize with tetragonal unit cells of the BaAl4-type. Representatives of these series, namely EuZn1.25Al2.75 and EuZnGa3, order ferromagnetically below 25 K and 14 K, respectively, due to the presence of divalent Eu ions. The other two ternaries studied, i.e. Eu2Zn14.32Al2.68 and Eu3Zn17.68Al4.32, adopt the rhombohedral Th2Zn17- and the tetragonal Ce3Zn22-type structure, respectively. Both compounds form with Eu2+ ions and possibly order antiferromagnetically at the lowest temperatures investigated.