Jo Y-R, Myeong S-H, Kim B-J
School of Materials Science and Engineering, Gwangju Institute of Science and Technology (GIST) 123 Cheomdangwagi-ro, Buk-gu Gwangju Korea
RSC Adv. 2018 Jan 30;8(10):5158-5165. doi: 10.1039/c7ra10865f. eCollection 2018 Jan 29.
Among the techniques to create VO nanostructures, the sol-gel method is the most facile and benefits from simple, manipulable synthetic parameters. Here, by utilizing various TEM techniques, we report the sequential morphological evolution of VO nanostructures in a sol-gel film spin-coated on a customized TEM grid, which underwent oxygen reduction as the annealing temperature increased. TEM dark-field imaging and Raman spectroscopy allowed us to confirm the sharp phase transition behavior of an individual nanowire by illustrating the effect of electrode-clamping-induced tensile stress on the nucleation of the R phase from the M1 phase. The electrical transport properties of a single-nanowire device fabricated on a customized TEM grid showed excellent control of the stoichiometry and crystallinity of the wire. These results offer critical information for preparing tailored VO nanostructures with advanced transition properties by the sol-gel method to enable the fabrication of scalable flexible devices.
在制备VO纳米结构的技术中，溶胶-凝胶法最为简便，且受益于简单、可控的合成参数。在此，通过运用各种透射电子显微镜（TEM）技术，我们报道了旋涂在定制TEM网格上的溶胶-凝胶薄膜中VO纳米结构的连续形态演变，随着退火温度升高，该薄膜经历了氧还原过程。TEM暗场成像和拉曼光谱使我们能够通过说明电极夹持引起的拉伸应力对从M1相到R相形核的影响，来确认单个纳米线的尖锐相变行为。在定制TEM网格上制造的单纳米线器件的电输运特性显示出对线的化学计量和结晶度的出色控制。这些结果为通过溶胶-凝胶法制备具有先进转变特性的定制VO纳米结构提供了关键信息，从而能够制造可扩展的柔性器件。
