论文标题
Crefeconi氮化物薄膜中的相形
Phase formation in CrFeCoNi nitride thin films
论文作者
论文摘要
作为单相合金，CRFECONI是一种面部中心立方（FCC）材料，与原型的高凝集Cantor合金CRFECONIMN有关。对于薄膜，大约等摩尔组成的CRFECONI在室温下通过磁控溅射在室温下生长时倾向于假设FCC结构。但是，对于在较高温度下生长的薄膜，通常无法实现单相固体溶液状态。对于基于Cantor合金的陶瓷（氮化物和氧化物），相对于过程参数（例如反应性气体量）非常敏感。这项研究结合了理论和实验方法，以了解含氮CRFECONI薄膜中的相形成。考虑三个竞争阶段（CRN，FE-NI和CO）的密度功能理论计算表明，混合的自由能，（CRFECONI）1-XNX固体溶液的最大值在x = 0.20-0.25时，并且在x小于0.20时，x = 0.20-0.25，delta g在x = 0.20-0.25时会降低。磁控溅射生长的（CRFECONI）1-XNX（X = 0.14-0.41）的薄膜显示，当X小于或等于0.22时，金属FCC的稳定性显示，当X的稳定性稳定时，当X的稳定性在X上稳定时，X结构时X的稳定性大于0.33，与理论上的预测一致。相反，在较高温度下生长的氮（x = 0.22）的膜显示出分离为CRN，Fe-Ni-rich and Co.的多个阶段。这些结果为小动物在低温下的生长条件的需求提供了一种解释，以便在低温下获得单相机制，以获取单相机制的较薄的较薄型，并在较薄的范围内进行较小的效果，并在较薄的范围内进行了效果，并且在范围内呈现效果，并且在范围内的效果效果，并且在某种程度上是在范围多组分陶瓷。
As a single-phase alloy, CrFeCoNi is a face centered cubic (fcc) material related to the archetypical high-entropy Cantor alloy CrFeCoNiMn. For thin films, CrFeCoNi of approximately equimolar composition tends to assume an fcc structure when grown at room temperature by magnetron sputtering. However, the single-phase solid solution state is typically not achieved for thin films grown at higher temperatures. The same holds true for Cantor alloy-based ceramics (nitrides and oxides), where phase formation is extremely sensitive to process parameters such as the amount of reactive gas. This study combines theoretical and experimental methods to understand the phase formation in nitrogen-containing CrFeCoNi thin films. Density functional theory calculations considering three competing phases (CrN, Fe-Ni and Co) show that the free energy of mixing, delta G of (CrFeCoNi)1-xNx solid solutions has a maximum at x = 0.20-0.25, and delta G becomes lower when x less than 0.20, greater than 0.25. Thin films of (CrFeCoNi)1-xNx (x = 0.14-0.41) grown by magnetron sputtering show stabilization of the metallic fcc when x lesser than or equal to 0.22 and the stabilization of the NaCl B1 structure when x is greater than 0.33, consistent with the theoretical prediction. In contrast, films with intermediate amounts of nitrogen (x = 0.22) grown at higher temperatures show segregation into multiple phases of CrN, Fe-Ni-rich and Co. These results offer an explanation for the requirement of kinetically limited growth conditions at low temperature for obtaining single-phase CrFeCoNi Cantor-like nitrogen-containing thin films and are of importance for understanding the phase-formation mechanisms in multicomponent ceramics.
