<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Chiang, T. C.</style></author><author><style face="normal" font="default" size="100%">Chou, M. Y.</style></author><author><style face="normal" font="default" size="100%">Kidd, T.</style></author><author><style face="normal" font="default" size="100%">Miller, T.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Fermi surfaces and energy gaps in Sn/Ge(111)</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of Physics-Condensed Matter</style></secondary-title><alt-title><style face="normal" font="default" size="100%">J. Phys.-Condes. Matter</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">ALPHA-PHASE</style></keyword><keyword><style  face="normal" font="default" size="100%">CHARGE-DENSITY-WAVE</style></keyword><keyword><style  face="normal" font="default" size="100%">DEFECTS</style></keyword><keyword><style  face="normal" font="default" size="100%">INTERFACES</style></keyword><keyword><style  face="normal" font="default" size="100%">PHASE-TRANSITION</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2002</style></year><pub-dates><date><style  face="normal" font="default" size="100%">Jan</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">&lt;Go to ISI&gt;://WOS:000173811800005</style></url></web-urls></urls><number><style face="normal" font="default" size="100%">1</style></number><volume><style face="normal" font="default" size="100%">14</style></volume><pages><style face="normal" font="default" size="100%">R1-R20</style></pages><isbn><style face="normal" font="default" size="100%">0953-8984</style></isbn><language><style face="normal" font="default" size="100%">English</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;One third of a monolayer of Sn adsorbed on Ge(111) undergoes a broad phase transition upon cooling from a (root3 x root3)R30degrees normal phase at room temperature to a (3 x 3) phase at low temperatures. Since band-structure calculations for the ideal (root3 x root3)R30degrees phase show no Fermi-surface nesting, the underlying mechanism for this transition has been a subject of much debate. Evidently, defects formed by Ge substitution for Sn in the adlayer, at a concentration of just a few percent, play a key role in this complex phase transition. Surface areas near these defects are pinned to form (3 x 3) patches above the transition temperature. Angle-resolved photoemission is employed to examine the temperature-dependent band structure, and the results show an extended gap forming in k-space as a result of band splitting at low temperatures. On account of the fact that the room temperature phase is actually a mixture of (root3 x root3)R30degrees areas and defect-pinned (3 x 3) areas, the band structure for the pure (root3 x root3)R30degrees phase is extracted by a difference-spectrum method. The results are in excellent agreement with band calculations. The mechanism for the (3 x 3) transition is discussed in terms of a response function and a tight-binding cluster calculation. A narrow bandwidth and a small group velocity near the Fermi surface render the system highly sensitive to surface perturbations, and formation of the (3 x 3) phase is shown to involve a Peierls-like lattice distortion mediated by defect doping. Included in the discussion, where appropriate, are dynamic effects and many-body effects that have been previously proposed as possible mechanisms for the phase transition.&lt;/p&gt;
</style></abstract><work-type><style face="normal" font="default" size="100%">Review</style></work-type><accession-num><style face="normal" font="default" size="100%">WOS:000173811800005</style></accession-num><notes><style face="normal" font="default" size="100%">&lt;p&gt;ISI Document Delivery No.: 520YRTimes Cited: 12Cited Reference Count: 31Cited References:      Perez R, 2001, PHYS REV LETT, V86, P4891, DOI 10.1103/PhysRevLett.86.4891     Rad MG, 2001, SURF SCI, V477, P227     Petaccia L, 2001, PHYS REV B, V63, part. no., DOI 10.1103/PhysRevB.63.115406     ASENSIO MC, 2001, UNPUB     ASENSIO MC, 2001, B AM PHYS SOC, V46, P849     OKASINSKI JS, 2001, UNPUB     OKASINSKI JS, 2001, B AM PHYS SOC, V46, P374     Kidd TE, 2000, PHYS REV LETT, V85, P3684, DOI 10.1103/PhysRevLett.85.3684     Perez R, 2000, APPL SURF SCI, V166, P45, DOI 10.1016/S0169-4332(00)00418-9     Gonzalez J, 2000, PHYS REV B, V62, P6928, DOI 10.1103/PhysRevB.62.6928     Avila J, 2000, APPL SURF SCI, V162, P48, DOI 10.1016/S0169-4332(00)00169-0     Uhrberg RIG, 2000, PHYS REV LETT, V85, P1036, DOI 10.1103/PhysRevLett.85.1036     Kidd TE, 2000, PHYS REV LETT, V84, P3023, DOI 10.1103/PhysRevLett.84.3023     Melechko AV, 2000, PHYS REV B, V61, P2235, DOI 10.1103/PhysRevB.61.2235     Ortega J, 2000, J PHYS-CONDENS MAT, V12, pL21, DOI 10.1088/0953-8984/12/1/104     Kidd TE, 1999, PHYS REV LETT, V83, P2789, DOI 10.1103/PhysRevLett.83.2789     Weitering HH, 1999, SCIENCE, V285, P2107, DOI 10.1126/science.285.5436.2107     Bunk O, 1999, PHYS REV LETT, V83, P2226, DOI 10.1103/PhysRevLett.83.2226     Melechko AV, 1999, PHYS REV LETT, V83, P999, DOI 10.1103/PhysRevLett.83.999     Zhang JD, 1999, PHYS REV B, V60, P2860, DOI 10.1103/PhysRevB.60.2860     Flores F, 1999, SURF REV LETT, V6, P411, DOI 10.1142/S0218625X99000421     Santoro G, 1999, PHYS REV B, V59, P1891, DOI 10.1103/PhysRevB.59.1891     Avila J, 1999, PHYS REV LETT, V82, P442, DOI 10.1103/PhysRevLett.82.442     *US DEP EN OFF SCI, 1999, COMPL SYST SCI 21 CE     Uhrberg RIG, 1998, PHYS REV LETT, V81, P2108, DOI 10.1103/PhysRevLett.81.2108     Le Lay G, 1998, APPL SURF SCI, V123, P440, DOI 10.1016/S0169-4332(97)00470-4     Goldoni A, 1997, PHYS REV LETT, V79, P3266, DOI 10.1103/PhysRevLett.79.3266     Carpinelli JM, 1997, PHYS REV LETT, V79, P2859, DOI 10.1103/PhysRevLett.79.2859     Carpinelli JM, 1996, NATURE, V381, P398, DOI 10.1038/381398a0     GORKOV L, 1989, CHARGE DENSITY WAVES     AVILA J, UNPUBChiang, TC Chou, MY Kidd, T Miller, TIOP PUBLISHING LTDBRISTOL&lt;/p&gt;
</style></notes><auth-address><style face="normal" font="default" size="100%">Univ Illinois, Dept Phys, Urbana, IL 61801 USA. Univ Illinois, Frederick Seitz Mat Res Lab, Urbana, IL 61801 USA. Georgia Inst Technol, Sch Phys, Atlanta, GA 30332 USA.Chiang, TC (reprint author), Univ Illinois, Dept Phys, 1110 W Green St, Urbana, IL 61801 USA</style></auth-address></record></records></xml>