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

利用分子束外延技术制备碱土金属六硼化物薄膜是一个极具挑战性的课题。在夏季期间克服了获得结晶薄膜的最初困难，并且现在已经成功地制备了相对高结晶度的硼化锶薄膜。除此之外，自制的CVD装置被构造，并且通过使用元素锶和癸硼烷作为前驱物的CVD过程成功地实现了六硼化锶薄膜的生长。我们已经进行了详细的研究的膜的结构和结晶度，并发现，高度结晶的SrB6可以沉积非常快，使用所述的CVD工艺。我们还测量了薄膜的热电性能，发现它们与报道的体积值相似，除了意外的高电阻率。这项工作是有意义的，因为它表明，使用元素金属源与癸硼烷一起可以是一种有效的方法来存款高度结晶的硼化物薄膜，这应该是有用的，在未来的研究中的金属硼化物薄膜。沉积过程的描述和热电性能的测量也为努力制造基于薄膜的热电纳米结构开辟了道路。还实现了令人惊讶的快速膜生长（“Deposition of Thermoelectric Strontium Hexaboride Thin Films by a Low Pressure CVD Method”Journal of Crystal Growth，in minor revision）。

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).