The presentation will be about investigations into the phase growth of SmFeAsO thin films in an ultra-high vacuum chamber
using pulsed laser deposition. SmFeAsO is a compensated semimetal and its related fluorine-doped version
SmFeAsO_1–xF_x is a member of the iron-oxypnictide subfamily of the iron-based superconductors. It is of
interest for its high critical temperature and unique electronic and magnetic properties. The parameter
window was sampled by more than 50 samples, varying temperature, target-substrate distance, fluence,
and laser wavelength, while keeping substrate (CaF2 (001) single crystals), target composition, and
background vacuum constant.
Thin films were characterized using X-ray diffractometry, scanning electron microscopy, and a physical
property measurement system. The large number of possible impurity phases complicated phase iden-
tification, motivating the development of a cross-validated, semi-automated peak assignment method.
It functions based on a tolerance model on peak positions, validated by higher-order peaks of the same
crystallites, and by assessing two-dimensional lattice commensurability with the substrate.
Furthermore, this method and the sample size enabled multivariate quadratic regression analysis,
providing strategies for optimization of the deposition process. It was found that the narrow deposition
window and impurity phase content in the PLD target are the main limitations to the achievement of
well-textured, phase-pure SmFeAsO thin films.