利用非平衡磁控溅射法制得厚度达到2.23 μm的掺铬含氢类金刚石(Cr-DLC)碳膜。 采用Raman光谱和XPS对制得的薄膜进行了结构和热稳定性等表征。 结果表明: 室温时, 薄膜在1 544 cm-1附近的Raman“G”峰归属于石墨结构中C—C键的伸缩振动, 即E2g 模式; 而1 367 cm-1附近的“D”峰归属于sp2碳环的“呼吸”振动模式, 即A1g模式; 计算得到薄膜sp3键的相对含量约为48at.%。 加热至300 ℃, 薄膜的Raman谱图与室温时相似, 表明此温度段薄膜的结构稳定, 未发生明显改变; 至400 ℃时, ID/IG值迅速增大, sp2键含量升高, 表明此时DLC膜发生了明显的结构变化, 开始发生石墨化。 继续升温, 膜中ID/IG比率增加, “G”峰位向高波数方向位移, 表明 sp2/sp3比率逐渐增大, 薄膜石墨化程度加强, sp2键的无序度逐渐降低, 最终导致薄膜的摩擦系数和磨损率等逐渐增大, 热稳定性逐渐降低。 退火600 ℃时, ID/IG值以及sp2键含量达到最大值, DLC薄膜失效。

Chromium doped amorphous hydrogenated carbon a-C∶H(Cr) films (2.23 μm in thickness)have been successfully prepared with unbalanced magnetron sputtering technology(UBMS) in this paper. Raman spectrum and X-ray photoelectron spectroscopy (XPS) have been used to study the structure and thermal stability of the Chromium doped diamond-like carbon films (Cr-DLC). The results indicate that, at the room temperature, the Raman absorption peak “G” near 1 580 cm-1was assigned to C—C stretching vibration mode (E2g) in the Cr-DLC films, while the peak “D” near 1 350 cm-1was assigned to sp2 breathing vibration mode (A1g). The relative concentration of sp3 bond in the film is at 48%. When heated till 300 ℃, the Raman pattern of sample is similar to that of the sample at room temperature, indicating the structure of Cr-DLC film is stable. At 400 ℃, the ratio of ID/IG and the concentration of sp2 bond clearly increase, indicating the change of the structure in the Cr-DLC and the appearance of graphitization. With temperature going up, the rise of ID/IG ratio and the shift of the peak “G” to high wavenumber show that the rise of sp2/sp3 ratio, the intensity of graphitization, and the decline of the disorder of sp2 in the Cr-DLC films lead to the increase of the friction coefficient and wearing rate and the decline of the Cr-DLC thermal stability. When the it is up to 600 ℃, the ratio of ID/IG and the concentration of sp2 bond reach the max value while the Cr-DLC film loses its efficacy.