MAPEX Research Highlights

Growth and characterization of epitaxially stabilized ceria(001) nanostructures on Ru(0001)

Jan Ingo Flege, Jan Höcker, Björn Kaemena, T. Onur Mentes, Alessandro Sala, Andrea Locatelli, Subhashis Gangopadhyay, Jerzy T. Sadowski, Sanjaya D. Senanayake and Jens Falta.

Nanoscale (2016) 8, 10849-10856.

doi:10.1039/C6NR02393B

We have studied (001) surface terminated cerium oxide nanoparticles grown on a ruthenium substrate using physical vapor deposition. Their morphology, shape, crystal structure, and chemical state are determined by low-energy electron microscopy and micro-diffraction, scanning probe microscopy, and synchrotron-based X-ray absorption spectroscopy. Square islands are identified as CeO2 nanocrystals exhibiting a (001) oriented top facet of varying size; they have a height of about 7 to 10 nm and a side length between about 50 and 500 nm, and are terminated with a p(2 × 2) surface reconstruction. Micro-illumination electron diffraction reveals the existence of a coincidence lattice at the interface to the ruthenium substrate. The orientation of the side facets of the rod-like particles is identified as (111); the square particles are most likely of cuboidal shape, exhibiting (100) oriented side facets. The square and needle-like islands are predominantly found at step bunches and may be grown exclusively at temperatures exceeding 1000 °C.

Updated by: MAPEX