Deposition and Phase Transformations of Ternary Al-Cr-O Thin Films
2011 (English)Licentiate thesis, comprehensive summary (Other academic)
This thesis concerns the ternary Al-Cr-O system. (Al1-xCrx)2O3 solid solution thin films with 0.6<x<0.7 were deposited on Si(001) substrates at temperatures of 400-500 °C by reactive radio frequency magnetron sputtering from metallic targets of Al and Cr in a flow controlled Ar / O2 gas mixture. As-deposited and annealed (Al1-xCrx)2O3 thin films were analyzed by x-ray diffraction, elastic recoil detection analysis, scanning electron microscopy, transmission electron microscopy, and nanoindentation. (Al1-xCrx)2O3 showed to have face centered cubic structure with lattice parameter of 4.04 Å, which is in contrast to the typical corundum structure reported for these films. The as-deposited films exhibited hardness of ~ 26 GPa and elastic modulus of 220-235 GPa. Phase transformation from cubic to corundum (Al0.32Cr0.68)2O3 starts at 925 °C. Annealing at 1000 °C resulted in complete phase transformation, while no precipitates of alumina and chromia were observed. Studies on kinetics of phase transformation showed a two-step thermally activated process; phase transformation and grain growth with the apparent activation energies 213±162 and 945±27 kJ/mol, respectively.
Place, publisher, year, edition, pages
Linköping: Linköping University Electronic Press , 2011. , 29 p.
Linköping Studies in Science and Technology. Thesis, ISSN 0280-7971 ; 1474
Thin Films, Hard Coatings
National CategoryOther Physics Topics
IdentifiersURN: urn:nbn:se:liu:diva-65700Local ID: LIU-TEK-LIC-2011:13ISBN: 978-91-7393-210-3OAI: oai:DiVA.org:liu-65700DiVA: diva2:398426
2011-04-15, Hörsal Planck, Fysikhuset, Campus Valla, Linköpings universitet, Linköping, 10:15 (English)
Andersson, Jon, Dr.
Hultman, Lars, ProfessorEklund, Per, Dr.
List of papers