强电场条件下二氧化钒薄膜的相变特性研究

Phase transition of vanadium dioxide thin films under strong electric field

为研究薄膜材料在强电场激励下的相变特性,采用直流磁控溅射工艺在硅衬底表面制备厚度不同的二氧化钒薄膜,搭建基于静电高压源和铜质电极夹具的材料相变特性测试系统。通过改变外施电场强度,研究薄膜材料的场致相变特性。结果表明:外施场强达到600 k V/m左右时,材料表现出明显的绝缘态-金属相变(MIT)特性;外施场强达到700k V/m时,材料电导率的变化幅度超过2.6个数量级,且远未达到饱和,随外场继续增加仍有很大上升空间。

In order to research phase transition characteristic of thin films under strong electric field,VO_2 thin films with different thickness were prepared on Si substrates by DC magnetron sputtering. A phase transition testing system was manufactured based on static high voltage source and copper electrode fixture. The field-induced phase transition of VO_2 thin films was researched through the variation of electric field intensity. The results show that the materials exhibit an obvious MIT feature at 600 k V/m.The variation of conductivity reaches more than 2.6 magnitudes at 700 k V/m and is far from reaching saturation,so there is still much room with the increase of external electric field.