热处理Co/C软X射线多层膜的掠入射反射率增强

ENHANCEMENT OF THE REFLECTIVITY OF Co/C SOFT X RAY MULTILAYERS AT GRAZING INCIDENCE BY THERMAL TREATMENT

研究了低温退火Ｃｏ／Ｃ软Ｘ射线多层膜中掠入射反射率的增强现象．通过测量一级调制峰强度随退火温度和时间的变化，测得了低至－１０－２５ｍ２ｓ－１的有效扩散系数．由于所研究的Ｃｏ／Ｃ多层膜的调制波长远大于ＣｏＣ系统的扩散临界波长，有效扩散系数近似等于真实宏观扩散系数．负的宏观扩散系数表明，在ＣｏＣ系统中有相分离的趋势．这一结果可解释为由Ｍｉｅｄｅｍａ宏观原子模型计算得到的正的ＣｏＣ系统的混合焓．

We report a significant increase of the reflectivity of a soft X ray Co/C multilayer at grazing incidence after low temperature annealing. By monitoring the enhancement of the first order modulation peak on annealing, the effective interdiffusion coefficient as low as -10 -25 m 2s -1 has been measured,which is nearly equal to the true macroscopic interdiffusion coefficient as the modulation wavelength of the Co/C multilayer studied is well above the critical wavelength. The negative true macroscopic interdiffusion coefficient indicates that there is a tendency to phase separation in the Co C system, which can be interpreted as the positive enthalpy of mixing calculated based on Miedema′s macroscopic atom model. The decrease of reflectivity above some anneal temperature is also discussed and explained as the competition between interfacial sharpness and roughness.