Growth temperature and relaxation of lattice strain in epitaxial Pt films exhibiting diffraction fringes

• Published in: Surface science Vol. 689; p. 121461
• Main Authors: Kasai, Masahiro, Dohi, Hideyuki
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.11.2019; Elsevier BV
• Subjects: Compressive properties; Diffraction patterns; Diffraction theory; Electrochemical analysis; Electron diffraction; Epitaxial growth; High energy electrons; Lattice strain; Misfit dislocations; Morphology; Strontium titanates; Substrates; Surface structure
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/j.susc.2019.121461

lHetero epitaxial growth of Pt on STO(111) was studied.lWell-defined Pt(111) surface was obtained.lLattice relaxation occurs at the growth temperature of 600 °C.lDiffraction fringes indicates in-plane strain as about 0.3%. We fabricated Pt epitaxial films on SrTiO3(111) using a dc-sputtering method. The surface structure, the surface morphology, and the electrochemical properties are discussed. Reflection high-energy electron diffraction (RHEED) observation reveals that epitaxial films are obtained at substrate temperatures higher than 450 °C. The RHEED patterns exhibit clear streaks up to the 1st order Laue zone, which indicates the high crystallinity and the atomically smooth surface. Oscillation in the intensity of the X-ray diffraction pattern is observed near the Pt-111 peak. It is caused by multiple scattering, showing the perfection in the lattice plane stacking along the out-of-plane direction. Analysis using a dynamic theory of diffraction shows that the film is subjected to a compressive in-plane lattice strain. The in-plane lattice parameter decreases by approximately 0.3%. The oscillation amplitude decreases at 600 °C, which suggests that the lattice relaxation occurs caused by misfit dislocation. [Display omitted]