**4. Conclusions**

In summary, VCN–Cu film was deposited using reactive magnetron sputtering:


**Acknowledgments:** Especially thanks to the financial support from National Natural Science Foundation of China (Grant No. 51374115 and 51574131).

**Author Contributions:** Lihua Yu conceived and designed the experiments; Lihua Yu and Fanjing Wu performed the experiments and analyzed the data; Hongbo Ju and Junhua Xu contributed to data analysis; Lihua Yu wrote the paper; all authors participated and discussed this work and contributed to the submitted and published manuscript.

**Conflicts of Interest:** The authors declare no conflict of interest.
