TY  - JOUR
AU  - Koslowski, H. R.
AU  - Schmitz, Janina
AU  - Linsmeier, Ch.
TI  - Temporally resolved LEIS measurements of Cr segregation after preferential sputtering of WCrY alloy
JO  - Nuclear instruments & methods in physics research / B Beam interactions with materials and atoms
VL  - 479
SN  - 0168-583X
CY  - Amsterdam [u.a.]
PB  - Elsevier
M1  - FZJ-2020-02311
SP  - 42 - 46
PY  - 2020
AB  - 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 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.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000570133600007
DO  - DOI:10.1016/j.nimb.2020.06.005
UR  - https://juser.fz-juelich.de/record/877589
ER  -