The quantitative analysis of thin specimens: a review of progress from the Cliff-Lorimer to the new zeta-factor methods.

A new quantitative thin-film X-ray analysis procedure termed the zeta-factor method is proposed. This new zeta-factor method overcomes the two major limitations of the conventional Cliff-Lorimer method for quantification: (1) use of pure-element rather than multielement, thin-specimen standards and (2) built-in X-ray absorption correction with simultaneous thickness determination. Combined with a universal, standard, thin specimen, a series of zeta-factors covering a significant fraction of the periodic table can be estimated. This zeta-factor estimation can also provide information about both the detector efficiency and the microscope-detector interface system. Light-element analysis can also be performed more easily because of the built-in absorption correction. Additionally, the new zeta-factor method has several advantages over the Cliff-Lorimer ratio method because information on the specimen thickness at the individual analysis points is produced simultaneously with compositions, thus permitting concurrent determination of the spatial resolution and the analytical sensitivity. In this work, details of the zeta-factor method and how it improves on the Cliff-Lorimer approach are demonstrated, along with several applications.