Temperature-controlled synthesis and characterization of Bi4Ge3O12 nanowires

Abstract Varying the heating temperature of a mixture of Bi and Ge powders, we have successfully prepared Bi 4 Ge 3 O 12 nanowires. The growth at 600 °C was mainly controlled via a vapor–liquid–solid process, whereas the growth at 800 °C was dominated by a vapor–solid mechanism. Although 600 °C-grown nanowires were amorphous, being comprised of Bi, Ge, O, and Au elements, the Bi and Au elements prevalently resided in the tip, playing a catalytic role in the nanowire growth. For 800 °C-grown nanowires, both the stem and tip were mainly comprised of cubic Bi 4 (GeO 4 ) 3 phase with additional Bi 2 O 3 and GeO 2 phases. Photoluminescence spectrum of 800 °C-grown nanowires exhibited GeO 2 -related emission band, as well as Bi 4 Ge 3 O 12 -related ones. The magnetic measurements showed that the Bi 4 Ge 3 O 12 nanowires exhibited a hysteresis loop, indicating ferromagnetic behavior.