Nanomechanical, structural, and transport properties of Bi3Se2Te thin films

作者：Phuoc Huu Le; Chiu Shao Pin; Jian Sheng Rui^*; Luo Chih Wei^*; Lin Jiunn Yuan; Lin Juhn Jong; Wu Kaung Hsiung; Gospodinov M

来源：Journal of Alloys and Compounds, 2016, 679: 350-357.

DOI：10.1016/j.jallcom.2016.03.226

• Topological insulator
• Bi3Se2Te
• Nanoindentation
• Weak antilocalization (WAL)
• Pulsed laser deposition (PLD)

New ternary phase of Bi3Se2Te thin films were successfully grown through pulsed laser deposition with a single Bi2Se2Te crystal as the target. Bi-rich and Se-and Te-deficient compositions deposited at a substrate temperature (T-s) of 250 degrees C and helium gas pressures (P-He) ranging from 2.0 x 10(-5) to 6.5 x 10(-1) Torr aided the formation of the dominant Bi-rich phase: Bi3Se2Te. The films were grown epitaxially on Al2O3 (001) substrates with Bi3Se2Te [001]//Al2O3 [001] and Bi3Se2Te [110]//Al2O3 [210]. An increase in P-He remarkably enhanced the hardness and Young's modulus of the films, primarily because of the decrease in nanograin size, following the HallePetch relationship. Moreover, the Bi3Se2Te films present linear magnetoresistance under a high perpendicular magnetic field (B >= 4 T) and twodimensional weak antilocalization effect under a low B (+/- 1 T) which may be attributed to topological insulator surface state (TSS). Clearly, further theoretical calculations and experiments are needed to confirm the suggested interpretation.

• 出版日期2016-9-15