title: Absence of evidence ≠ evidence of absence: statistical analysis of inclusions in multiferroic thin films.
abstract: Assertions that a new material may offer particularly advantageous properties should always be subjected to careful critical evaluation, especially when those properties can be affected by the presence of inclusions at trace level. This is particularly important for claims relating to new multiferroic compounds, which can easily be confounded by unobserved second phase magnetic inclusions. We demonstrate an original methodology for the detection, localization and quantification of second phase inclusions in thin Aurivillius type films. Additionally, we develop a dedicated statistical model and demonstrate its application to the analysis of Bi(6)Ti(2.8)Fe(1.52)Mn(0.68)O18 (B6TFMO) thin films, that makes it possible to put a high, defined confidence level (e.g. 99.5%) to the statement of 'new single phase multiferroic materials'. While our methodology has been specifically developed for magnetic inclusions, it can easily be adapted to any other material system that can be affected by low level inclusions.
authors.affiliation: 1] Tyndall National Institute, University College Cork, 'Lee Maltings', Dyke Parade, Cork, Ireland [2] Department of Chemistry, University College Cork, Cork, Ireland.
authors.forename: Michael
authors.initials: M
authors.lastname: Schmidt
authors.affiliation: 1] Tyndall National Institute, University College Cork, 'Lee Maltings', Dyke Parade, Cork, Ireland [2] School of Mathematical Sciences, University College Cork, Ireland.
authors.forename: Andreas
authors.initials: A
authors.lastname: Amann
authors.affiliation: Tyndall National Institute, University College Cork, 'Lee Maltings', Dyke Parade, Cork, Ireland.
authors.forename: Lynette
authors.initials: L
authors.lastname: Keeney
authors.affiliation: 1] Tyndall National Institute, University College Cork, 'Lee Maltings', Dyke Parade, Cork, Ireland [2] Department of Chemistry, University College Cork, Cork, Ireland.
authors.forename: Martyn E
authors.initials: ME
authors.lastname: Pemble
authors.affiliation: 1] Tyndall National Institute, University College Cork, 'Lee Maltings', Dyke Parade, Cork, Ireland [2] Department of Chemistry, University College Cork, Cork, Ireland [3] Centre for Research on Adaptive Nanostructures and Nanodevices, Trinity College Dublin, Dublin 2, Ireland.
authors.forename: Justin D
authors.initials: JD
authors.lastname: Holmes
authors.affiliation: Tyndall National Institute, University College Cork, 'Lee Maltings', Dyke Parade, Cork, Ireland.
authors.forename: Nikolay
authors.initials: N
authors.lastname: Petkov
authors.affiliation: 1] Tyndall National Institute, University College Cork, 'Lee Maltings', Dyke Parade, Cork, Ireland [2] Department of Chemistry, University College Cork, Cork, Ireland [3] Department of Materials, Royal School of Mines, Imperial College London, South Kensington Campus, London SW7 2AZ, UK.
authors.forename: Roger W
authors.initials: RW
authors.lastname: Whatmore