We report the sputter deposition of Cu-7V and Cu-27V (at.%) alloy films in an attempt to yield a “clean” alloy to investigate nanocrystalline stability. Films grown in high vacuum chambers can mitigate processing contaminates which convolute the identification of nanocrystalline stability mechanism(s). The initial films were very clean with carbon and oxygen contents ranging between ~0.01 and 0.38 at.%. Annealing at 400 °C/1 h facilitated the clustering of vanadium at high-angle grain boundary triple junctions. At 800 °C/1 h annealing, the Cu-7V film lost its nanocrystalline grain sizes with the vanadium partitioned to the free surface; the Cu-27V retained its nanocrystalline grains with vanadium clusters in the matrix, but surface solute segregation was present. Though the initial alloy and vacuum annealing retained the low contamination levels sought, the high surface area-to-volume ratio of the film, coupled with high segregation tendencies, enabled this system to phase separate in such a manner that the stability mechanisms that were to be studied were lost at high temperatures. This illustrates obstacles in using thin films to address nanocrystalline stability.

我们报告了溅射沉积Cu-7V和Cu-27V（at。％）合金膜的过程，以试图生产出一种“干净的”合金来研究纳米晶的稳定性。在高真空室中生长的薄膜可以减轻加工污染，这些污染使对纳米晶稳定机制的识别变得复杂。初始膜非常干净，碳和氧含量在〜0.01至0.38 at。％之间。400°C / 1 h退火有助于钒在高角度晶界三重结处聚集。在800°C / 1 h退火温度下，Cu-7V薄膜失去了纳米晶粒尺寸，钒分配到了自由表面上。Cu-27V在基体中保留了带有钒簇的纳米晶粒，但存在表面溶质偏析。尽管最初的合金和真空退火工艺保持了较低的污染水平，但薄膜的高表面积/体积比以及高偏析趋势使该系统能够以如下方式相分离：被研究者在高温下迷路了。这说明了在使用薄膜解决纳米晶体稳定性方面的障碍。