Properties of Bi2Te3-Sb2Te3 Alloys

The phase diagram for the Bi2Te3–Sb2Te3 pseudo-binary system is of the solid-solution type, where the distribution coefficient k is equal to unity at 33.3 and 66.7 mole % Sb2Te3. The c lat tice parameter remains essentially constant across the diagram at 30.49 Å for both slowly crystallized and quenched alloys. For quenched alloys the a lattice parameter decreases almost linearly, from a value of 4.487 Å, for pure Bi2Te3, to a value of 4.275 Å, for pure Sb2Te3; however, a significant contraction from linear variation is found in slowly crystallized materials. EG diminishes in an essentially linear fashion from 0.16 eV, for pure Bi2Te3, to 0.12 eV at 24.2 mole % Sb2Te3 in both slowly crystallized and quenched materials. EG remains approximately constant from 24.2 to 66.7 mole % Sb2Te3 for slowly crystallized materials but continues to drop for quenched materials.