ISO/TC 202/SC 3 - Analytical electron microscopy

This document specifies a determination procedure of energy resolution in the scanning transmission electron microscope or the transmission electron microscope equipped with the electron energy loss (EEL) spectrometer. This document is applicable to both in-column type EEL spectrometer and post-column type EEL spectrometer. These EEL signal detecting systems are applicable to a parallel detecting system and a serial detecting system.

ISO 25498:2018 specifies the method of selected area electron diffraction (SAED) analysis using a transmission electron microscope (TEM) to analyse thin crystalline specimens. This document applies to test areas of micrometres and sub-micrometres in size. The minimum diameter of the selected area in a specimen which can be analysed by this method is restricted by the spherical aberration coefficient of the objective lens of the microscope and approaches several hundred nanometres for a modern TEM. When the size of an analysed specimen area is smaller than that restriction, this document can also be used for the analysis procedure. But, because of the effect of spherical aberration, some of the diffraction information in the pattern can be generated from outside of the area defined by the selected area aperture. In such cases, the use of microdiffraction (nano-beam diffraction) or convergent beam electron diffraction, where available, might be preferred. ISO 25498:2018 is applicable to the acquisition of SAED patterns from crystalline specimens, indexing the patterns and calibration of the diffraction constant.

ISO 29301:2017 specifies a calibration procedure applicable to images recorded over a wide magnification range in a transmission electron microscope (TEM). The reference materials used for calibration possess a periodic structure, such as a diffraction grating replica, a super-lattice structure of semiconductor or an analysing crystal for X-ray analysis, and a crystal lattice image of carbon, gold or silicon. This document is applicable to the magnification of the TEM image recorded on a photographic film, or an imaging plate, or detected by an image sensor built into a digital camera. This document also refers to the calibration of a scale bar. This document does not apply to the dedicated critical dimension measurement TEM (CD-TEM) and the scanning transmission electron microscope (STEM).

ISO 20263:2017 specifies a procedure for the determination of averaged interface position between two different layered materials recorded in the cross-sectional image of the multi-layered materials. It is not intended to determine the simulated interface of the multi-layered materials expected through the multi-slice simulation (MSS) method. This document is applicable to the cross-sectional images of the multi-layered materials recorded by using a transmission electron microscope (TEM) or a scanning transmission electron microscope (STEM) and the cross-sectional elemental mapping images by using an energy dispersive X-ray spectrometer (EDS) or an electron energy loss spectrometer (EELS). This document is also applicable to the digitized image recorded on an image sensor built into a digital camera, a digital memory set in the PC or an imaging plate and the digitalized image converted from an analogue image recorded on the photographic film by an image scanner.

ISO 19214:2017 prescribes a method for the determination of apparent growth direction by transmission electron microscopy. It is applicable to all kinds of wirelike crystalline materials fabricated by various methods. This document can also guide in ascertaining an axis direction of the second-phase particles with a rod-like or polygonal shape in steels, alloys or other materials. The applicable diameter or width of the crystals to be tested is in the range of tens to hundreds of nanometres, depending on the accelerating voltage of the TEM and the material itself. NOTE In the present document, wirelike crystals, beltlike crystals, needle-shaped second-phase particles, etc. are all subsumed by the broad category of wirelike crystals.

ISO 25498:2010 specifies the method of selected-area electron diffraction (SAED) analysis using a transmission electron microscope (TEM) to analyse micrometer and sub-micrometer sized areas of thin crystalline specimens. Such specimens can be obtained in the form of thin sections from a variety of metallic and non-metallic materials, as well as fine powders, or alternatively by the use of extraction replicas. The minimum diameter of the selected area in a specimen which can be analysed by this method depends on the spherical aberration coefficient of the objective lens of the microscope and approaches 0,5 mm for a modern TEM. When the diameter of an analysed specimen area is smaller than 0,5 mm, the analysis procedure can also be referred to ISO 25498:2010 but, because of the effect of spherical aberration, some of the diffraction information in the pattern can be generated from outside of the area defined by the selected-area aperture. In such cases, the use of microdiffraction or convergent beam electron diffraction, where available, might be preferred. The success of the selected-area electron diffraction method relies on the validity of indexing the diffraction patterns arising, irrespective of which axis in the specimen lies parallel to the incident electron beam. Such analysis is therefore aided by specimen tilt and rotation facilities. ISO 25498:2010 is applicable to acquisition of SAED patterns from crystalline specimens, indexing the patterns and calibration of the diffraction constant.

ISO 29301:2010 specifies a calibration procedure applicable to images recorded over a wide magnification range in a transmission electron microscope (TEM). The reference materials used for calibration possess a periodic structure, such as a diffraction grating replica, a super-lattice structure of semiconductor or an analysing crystal for X-ray analysis, and a crystal lattice image of carbon, gold or silicon. ISO 29301:2010 is applicable to the magnification of the TEM image recorded on a photographic film, or an imaging plate, or detected by an image sensor built into a digital camera. ISO 29301:2010 also refers to the calibration of a scale bar. ISO 29301:2010 does not apply to the dedicated critical dimension measurement TEM (CD-TEM) and the scanning transmission electron microscope (STEM)