Magnesium silicide (Mg2Si) is expected as a semiconductor material for thermoelectric devices though synthesis of the thin film has been difficult due to difference in thermodynamic properties of Mg and Si. The authors have succeeded in preparing a poly-crystalline Mg2Si thin film with a thickness of ~1m and strong (111) orientation on a sapphire substrate (r plane). The method includes sputter deposition of a Mg/Si bilayer from independent Mg and Si sources and post-annealing (2 h) in argon gas at 900 Pa. The optimum annealing temperature for the Mg2Si film synthesis is found to be 300-400°C.

Magnesium silicide (Mg2Si) is expected as a semiconductor material for thermoelectric devices though synthesis of the thin film has been difficult due to difference in thermodynamic properties of Mg and Si. The authors have succeeded in preparing a poly-crystalline Mg2Si thin film with a thickness of ~1m and strong (111) orientation on a sapphire substrate (r plane). The method includes sputter deposition of a Mg/Si bilayer from independent Mg and Si sources and post-annealing (2 h) in argon gas at 900 Pa. The optimum annealing temperature for the Mg2Si film synthesis is found to be 300-400°C.