Structure and mechanical properties of nitrogen-containing Zr-Cu based thin films deposited by pulsed magnetron sputtering
Structure and mechanical properties of nitrogen-containing Zr-Cu based thin films deposited by pulsed magnetron sputtering
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脉冲磁控溅射沉积含氮Zr-Cu基薄膜的结构与力学性能
DOI：
10.1088/0022-3727/41/15/155301
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发表时间：
2008
期刊：
影响因子：
--
通讯作者：
Jimenez O
中科院分区：
文献类型：
--
作者：
Jimenez O
采用脉冲直流磁控溅射法制备了不同成分（不同Zr/Cu比和氮含量）的锆铜薄膜。在低混相的二元Zr-Cu体系中加入氮作为溶液硬化和/或氮形成元素，可以沉积两相（或多相）纳米结构涂层。利用x射线衍射和扫描电镜对涂层的结构和形貌进行了研究。通过定量能量色散x射线分析获得了元素组成和Zr/Cu原子比。通过纳米压痕测量来评估涂层的硬度和弹性模量。发现涂层结构取决于化学成分；当氮含量较低时，涂层呈现柱状结构，而当氮流量最大时，涂层结构致密。少氮或无氮（n2气体流速为0和1 sccm）制备的ZrCu (N)薄膜呈现部分非晶结构，具有宽、低强度的Zr和Cu x射线衍射峰。富Zr涂层在n2流速增加（3 sccm）的情况下形成纳米晶Zr和ZrN相，而在相同n2流速下，富Cu涂层的非晶化增加，随后出现Cu偏析。在最高n2流速下，制备出5 sccm的zrn基结晶涂层。在0、1和3 sccm n2流速下沉积的富Zr涂层（Zr/Cu比为~ 2.2-6.2）的硬度值略高于Zr/Cu比较低的涂层，而在大多数情况下，弹性模量呈现相反的趋势。这种行为被证明与薄膜的化学成分和所得到的组成相的预期力学性能有很好的关联——例外是无氮涂层，它（令人惊讶地）随着铜含量的增加而出现较低的弹性模量。
Pulsed-dc magnetron sputtered zirconium–copper films were deposited with a range of different compositions (of varying Zr/Cu ratio and nitrogen content). Adding nitrogen to the low-miscibility binary Zr–Cu system as a solution hardening and/or nitride-forming element permits the deposition of two-(or multi-) phase nanostructured coatings. Structure and morphology of the coatings was studied by means of x-ray diffraction and scanning electron microscopy. Elemental compositions and Zr/Cu atomic ratios were obtained by quantitative energy-dispersive x-ray analysis. Nanoindentation measurements were made to evaluate coating hardness and elastic modulus. Coating structure was found to depend on the chemical composition; at low nitrogen contents coatings exhibited a columnar morphology, while the maximum N 2 flow rate used resulted in a compact and fully dense coating structure. ZrCu (N) films produced with little or no nitrogen (N 2 gas flow rates of 0 and 1 sccm) showed a partially amorphous structure with broad, low intensity Zr and Cu x-ray diffraction peaks. An increase in N 2 flow rate (3 sccm) developed coatings with nanocrystalline Zr and ZrN phases for the Zr-rich coatings, while increased amorphization, followed by Cu segregation, was observed for Cu-rich coatings deposited at the same N 2 flow rate. At the highest N 2 flow rate of 5 sccm crystalline ZrN-based coatings were produced. Zr-rich coatings deposited at 0, 1 and 3 sccm N 2 flow rates (with Zr/Cu ratios of∼ 2.2–6.2) demonstrated slightly higher hardness values than coatings exhibiting lower Zr/Cu ratios, while the elastic modulus in the majority of cases showed an opposite trend. This behaviour is shown to correlate well with film chemical composition and the expected mechanical properties of the resulting constituent phases—the exception being the nitrogen-free coatings which (surprisingly) appeared to develop a lower elastic modulus with increasing copper content.