ISO/AWI 25871

Проект данного международного стандарта был подготовлен рабочей группой.

Тезис

This document specifies a method for determining the thickness of thin crystalline specimens by convergent beam electron diffraction (CBED) using a transmission electron microscope/ scanning transmission electron microscope (TEM/STEM). This method is applicable to determine the thickness of thin crystal specimens. In principle, all crystalline thin specimens, including metalls, ceramics, semiconductors, mineral substance etc, can be studied by CBED method. However, deformation or defects of the specimen may affect the quality of the CBED pattern hence the resullts. The thickness that can be measured is in the range of tens to hundreds of nano-metres. The maximum measurable thickness is limited by the energy of the incident electron beam and mass thickness of the specimen. However, the minimum value of the measurable thickness depends on the diffraction condition of the diffracted beam, which is excited for the mesurement. When the specimen is thin enough the adequate dynamic diffraction fringes will not appear. In such case, this CBED technique is not able to carried out to measure the specimen thickness, owing to that obtaining the dynamic diffraction contrast within the diffracted disc is the prerequisite for CBED study. Since the thickness of the thin specimens is often uneven, the thickness determined by CBED method is the local thickness of a specimen area where is illuminated by the incident beam. This document is not applicable for non-crystalline specimens.

Общая информация

Текущий статус
: В стадии разработки

Этап
: Регистрация новой рабочей темы в программе работ ТК/ПК [20.00]
Версия
: 1
Технический комитет :
ISO/TC 202/SC 3
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