کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5396116 | 1505741 | 2013 | 5 صفحه PDF | دانلود رایگان |
The magnetic phase transitions for Gd(0Â 0Â 0Â 1) grown on W(1Â 1Â 0) - a bulk transition at 293Â K and a surface transition about 85Â K above this - are found to influence the energy separation of the Gd 5s and 4s core-photoelectron doublets. The 5s doublet separation ÎE5s changes over a range of temperatures spanning these transitions, and decreases by a maximum of 60Â meV in this region, but then recovers its original value; the 4s doublet shows a smaller change in the reverse direction, which does not recover at high temperature. Some of these effects are semi-quantitatively understood from free-atom multiplet theory and from theoretical calculations based on all-electron LDA+U calculations including 4f electron correlation effects. However, the high-temperature behavior of the data also suggest a dynamical nature to these effects via spin-dependent electron screening that is influenced by magnetic fluctuations. Several avenues for studying such effects in a time-resolved manner in future experiments are discussed.
⺠Gd 5s and 4s multiplet splittings of Gd(0001) change during magnetic transitions. âºÂ·Atomic multiplet theory and LDA+U calculations partially explain these results. âºÂ·Provide a novel probe of dynamical spin-dependent screening/magnetic fluctuations. ⺠Suggest future experiments in a time-resolved mode, e.g. using free electron lasers.
Journal: Journal of Electron Spectroscopy and Related Phenomena - Volume 189, August 2013, Pages 152-156