Convergent-beam electron diffraction in the high-voltage electron microscope with continuously variable reference voltage for lenses and alignments

Abstract

A device which provides a continuously variable reference voltage for lenses and alignments is developed for the high-voltage scanning transmission electron microscope H-1250ST. When continuously varying the operating voltage, compensation for all lenses and alignments is easily performed by the adoption of the device. The device is especially useful for forming the convergent-beam electron diffraction (CBED) patterns at any accelerating voltage. The performance of the device is demonstrated by observing the CBED patterns. Large-angle CBED patterns are taken for Si- and Y-based high- T c superconductors at various voltages. Systematic critical voltages of Y-based high- T c superconductors are measured for the 400 and 220 reflections.