X-ray microdiffraction study of growth modes and crystallographic tilts in oxide films on metal substrates.
The crystallographic texture of thin-film coatings plays an essential role in determining such diverse materials properties as wear resistance, recording density in magnetic media and electrical transport in superconductors. Typically, X-ray pole figures provide a macroscopically averaged description of texture, and electron backscattering provides spatially resolved surface measurements. In this study, we have used focused, polychromatic synchrotron X-ray microbeams to penetrate multilayer materials and simultaneously characterize the local structure, orientation and strain tensor of different heteroepitaxial layers with submicrometre resolution. Grain-by-grain microstructural studies of cerium oxide films grown on textured nickel foils reveal two distinct kinetic growth regimes on vicinal surfaces: ledge growth at elevated temperatures and island growth at lower temperatures. In addition, a combinatorial approach reveals that crystallographic tilting associated with these complex interfaces is qualitatively described by a simple geometrical model applicable to brittle films on ductile substrates. The sensitivity of conducting percolation paths to tilt-induced texture improvement is demonstrated.
Budai
John D
JD
Condensed Matter Sciences Division, Oak Ridge National Laboratory, PO Box 2008, Oak Ridge, Tennessee 37831, USA. budaijd@ornl.gov
Yang
Wenge
W
Tamura
Nobumichi
N
Chung
Jin-Seok
JS
Tischler
Jonathan Z
JZ
Larson
Bennett C
BC
Ice
Gene E
GE
Park
Chan
C
Norton
David P
DP
D002563:Cerium / Q000737:chemistry; D018360:Crystallography, X-Ray; D008670:Metals; D010087:Oxides / Q000737:chemistry*
D008670:Metals; D010087:Oxides; D002563:Cerium; C030583:ceric oxide