ナノ薄膜の創製と熱電的性質の解明および閉じ込め効果の検証

利用分子束外延(MBE)技术制备碱土六硼化物薄膜是一项极具挑战性的课题。在夏季期间克服了获得结晶薄膜的最初困难，现在已经成功地制备了结晶度相对较高的硼化锶薄膜。此外，还搭建了自制的CVD装置，并以元素锶和十硼烷为原料，通过CVD工艺成功地生长了六硼化锶薄膜。我们对薄膜的结构和结晶度进行了详细的研究，发现使用所描述的CVD工艺可以非常快地沉积高结晶度的SrB6。我们还测量了薄膜的热电性能，发现除了出人意料的高电阻率外，它们与报道的体积值相似。这项工作具有重要的意义，因为它表明，使用元素金属源和十硼烷可以有效地沉积高晶态的硼化物薄膜，这将在未来的金属硼化物薄膜的研究中得到应用。沉积过程的描述和热电性能的测量也为制备用于热电的薄膜基纳米结构开辟了道路。薄膜的生长速度也出奇的快(《低压CVD法沉积热电六硼化锶薄膜》，《晶体生长杂志》，稍作修订)。

The very challenging topic of fabricating thin films of alkaline earth hexaborides using the molecular beam epitaxy (MBE) technique was carried out. Initial difficulties with achieving crystalline films were overcome during the summer, and strontium boride thin films of relatively high crystallinity have now been successfully fabricated.In addition to this, a home-made CVD was constructed, and the successful growth of strontium hexaboride thin films by a CVD process using elemental strontium and decaborane as the precursors, was achieved. We have performed a detailed study of the structure and crystallinity of the films and found that highly crystalline SrB6 can be deposited remarkably fast using the described CVD process. We also measured the thermoelectric properties of the films and found them to be similar to reported bulk values apart from an unexpectedly high electrical resistivity. The work is significant because it shows that using elemental metal sources together with decaborane can be an effective way to deposit highly crystalline boride thin films, which should be useful in future studies of metal boride thin films. The description of the deposition process and measurement of thermoelectric properties also opens the way for efforts to fabricate thin film based nanostructures for thermoelectrics. Surprisingly fast film growth was also achieved (“Deposition of Thermoelectric Strontium Hexaboride Thin Films by a Low Pressure CVD Method" Journal of Crystal Growth, in minor revision).