Advanced Scanning Electron Microscopy and X-Ray Microanalysis

Studies of high temperature ternary phases in mixed-metal-rich early transition metal sulfide and phosphide systems

“…The results of SEM-EDS analysis on Zr^gTag^S^o, given in Table 3.1, showed that no Ti was present. The detected level of oxygen in the ZrggTag ^S^o sample was 0.4 oxygens per formula unit but the lowest possible detection sensitivity (under optimum conditions) for the technique of SEM-EDS is approximately 1 wt% for a light element such as oxygen in a heavy metal matrix [90] which is approximately 1 oxygen per formula unit in this system. The presence of oxygen in this sample was therefore not reliably determined with this technique and may or may not have been real.…”

A New Approach to the Habit Determination of Nano-Objects by SEM

“…The main difficulties encountered in performing SEM metrology are associated with the mechanism of image formation, when images are formed in the course of electron beam scanning over the surface of the object and represent the sum of sequential responses (from secondary and backscattered electrons) generated by the object in response to inelastic scattering of electrons of an illuminating beam (probe) (the probe is a cross section of the electron beam by the surface of the object). The intensity profiles in SEM images depend on the energy of electrons in the illuminating beam, the probe size, the material of the object and its relief; they reflect the probability distribution of the escape of recoil electrons from different points [16][17]. As a result, the intensity profiles have the shape of curves on which points corresponding to the edges of the object cannot be determined, i.e., the sizes of the object cannot be directly measured.…”

“…Therefore, in order to measure sizes of an object with a scanning electron microscope, it is recommended to use an approach based on the simulation of SEM images. This approach involves Monte Carlo calculations of the probabilistic cascade of collisions upon injection of a single electron into the object (and, correspondingly, the escape of recoil electrons) as a function of the energy of this electron and the atomic number of the material under investigation, the averaging/summation of the results and subsequent fitting of the calculated curve to the experimental curve by varying the sizes of the object (the profile fitting method) [16].…”

Influencia de los tratamientos de revenidos intercríticos en la concentración de níquel correspondiente, a partículas de austenita residual en un acero con 9% Ni

“…Los resultados obtenidos por tal sistema (fracción de concentración de elementos químicos) dependen de algunos datos de entrada, entre los que se destacan el espesor del área analizada (muy variable) y la densidad del material. Los resultados pueden variar de acuerdo con el modelo escogido para el cálculo y, en el caso del EDAX CM-120, el modelo patrón fue el de Zaluzek (9). No obstante su aplicación requiere el conocimiento del espesor del área analizada.…”

“…Para superar los inconvenientes anteriores el mejor método está en convertir las intensidades integradas de los rayos X en porcentaje en peso de los elementos, utilizando una relación entre las intensidades integradas conocida como método de CliffLorimer (9) c,…”