论文标题
优先溅射WCRY合金后，CR分离的时间分离的临时休闲测量值
Temporally resolved LEIS measurements of Cr segregation after preferential sputtering of WCrY alloy
论文作者
论文摘要
使用低能离子散射（LEE）研究了CR向WCRY SMART合金表面的热驱动分离的动态行为。在室温下用500 ev d $ _2^+$离子溅起WCRY样品会导致优先去除较轻的合金成分，并导致几乎纯W的表面层。在高于700 K以上的高温下，Cr原子的隔离向表面固定并防止形成纯W层。样品的同时加热和溅射导致表面状态，反映了溅射去除和隔离通量之间的平衡，并且由于热驱动的分离而偏离了平衡。停止溅射离子光束使系统可以放松并朝着隔离平衡发展。 W和Cr表面覆盖的时间变化的时间常数是从一系列LEIS测量中获得的。隔离焓取决于各种样品温度的时间常数。
The dynamic behaviour of thermally driven segregation of Cr to the surface of WCrY smart alloy is studied with low energy ion scattering (LEIS). Sputtering the WCrY sample with 500 eV D$_2^+$ ions at room temperature results in preferential removal of the lighter alloy constituents and causes an almost pure W surface layer. At elevated temperatures above 700 K the segregation of Cr atoms towards the surface sets in and prevents the formation of a pure W layer. The simultaneous heating and sputtering of the sample leads to a surface state which reflects the balance between sputter removal and segregation flux, and deviates from the equilibrium due to thermally driven segregation. Stopping the sputter ion beam allows the system to relax and develop toward the segregation equilibrium. The time constants for the temporal changes of W and Cr surface coverage are obtained from a series of LEIS measurements. The segregation enthalpy is determined from the time constants obtained for various sample temperatures.
