Nature of the root 3 alpha to 3 x 3 reversible phase transition at low temperature in Sn/Ge (111)
2001 (English)In: Applied Surface Science, ISSN 0169-4332, E-ISSN 1873-5584, Vol. 175, 201-206 p.Article in journal (Refereed) Published
Metal-induced superstructures on semiconductors at sub-monolayer coverages have been mostly studied at, or above, room temperature. Yet, recently, several reversible phase transitions, like, e.g. the root3 x root3 alpha to 3 x 3 transition in the Pb, Sn/Ge (111) prototypical systems, have been discovered below RT. The origin of these new reconstructions is very intriguing and is a matter of strong debate. Some groups privilege electronic instabilities leading to charge ordered states at low temperature (LT), while other favor dynamical effects and the formation a kind of bond density waves (BDW's) at LT. Besides these intrinsic behaviors, the role played by inevitable defects has also been emphasized by several authors. Focussing especially on the Sn/Ge (111) system, we present a detailed analysis of the spectroscopic signatures of each phase in photoemission measurements. We show that static models are impossible to reconcile with these measurements.
Place, publisher, year, edition, pages
2001. Vol. 175, 201-206 p.
semiconductors, photoemission, transition, charge-density-wave, distortion, surfaces, defects
IdentifiersURN: urn:nbn:se:kth:diva-20678ISI: 000169032100034OAI: oai:DiVA.org:kth-20678DiVA: diva2:339374
QC 201005252010-08-102010-08-10Bibliographically approved