Danoix F, Grancher G, Bostel A, Blavette D
Groupe de Physique Des Matériaux, UMR CNRS 6634, Institut de Matériaux de Rouen, Université de Rouen, Site Universitaire du Madrillet, Avenue de l'Université, 76 801 Saint Etienne du Rouvray, France.
Ultramicroscopy. 2007 Sep;107(9):734-8. doi: 10.1016/j.ultramic.2007.02.006. Epub 2007 Feb 25.
Atom probe is a very powerful instrument to measure concentrations on a sub nanometric scale [M.K. Miller, G.D.W. Smith, Atom Probe Microanalysis, Principles and Applications to Materials Problems, Materials Research Society, Pittsburgh, 1989]. Atom probe is therefore a unique tool to study and characterise finely decomposed metallic materials. Composition profiles or 3D mapping can be realised by gathering elemental composition measurements. As the detector efficiency is generally not equal to 1, the measured compositions are only estimates of actual values. The variance of the estimates depends on which information is to be estimated. It can be calculated when the detection process is known. These two papers are devoted to give complete analytical derivation and expressions of the variance on composition measurements in several situations encountered when using atom probe. In the first paper, we will concentrate on the analytical derivation of the variance when estimation of compositions obtained from a conventional one dimension (1D) atom probe is considered. In particular, the existing expressions, and the basic hypotheses on which they rely, will be reconsidered, and complete analytical demonstrations established. In the second companion paper, the case of 3D atom probe will be treated, highlighting how the knowledge of the 3D position of detected ions modifies the analytical derivation of the variance of local composition data.
原子探针是一种非常强大的仪器，可在亚纳米尺度上测量浓度[M.K. 米勒，G.D.W. 史密斯，《原子探针微分析：原理及对材料问题的应用》，材料研究学会，匹兹堡，1989年]。因此，原子探针是研究和表征精细分解金属材料的独特工具。通过收集元素组成测量数据，可以实现成分分布或三维映射。由于探测器效率通常不等于1，所测量的成分只是实际值的估计。估计值的方差取决于要估计的信息。当检测过程已知时，可以计算方差。这两篇论文致力于给出在使用原子探针时遇到的几种情况下成分测量方差的完整解析推导和表达式。在第一篇论文中，我们将专注于在考虑从传统一维（1D）原子探针获得的成分估计时方差的解析推导。特别是，将重新审视现有表达式及其所依赖的基本假设，并建立完整的解析论证。在第二篇配套论文中，将处理三维原子探针的情况，突出检测离子的三维位置信息如何改变局部成分数据方差的解析推导。
