Crystal standard for electron diffraction investigations - using thallium chloride mixed with amorphous stabilising phase

摘要

Standard prepn. suitable for electron diffraction diagrams, using a multiphase layer of thallium chloride, where the layer contains a stabilising phase (1) which is amorphous when exposed to electrons due to its coherent lattice divisions being below 3 nm. Phase (1) is pref. (a) an oxide with high m. pt., esp. SiO, SiO2, or Al2O3; or (b) a nitride or (c) carbon. An esp. pref. layer is thallium chloride contg. 40-70 vol.% SiO. The layer is pref. located on a thin film or membrane of collodion clamped on the diaphragm of an electron microscope. Used in examination of substances by electron diffraction, using an electron microscope. The disadvantage of TlCl crystals as a standard is their low m.pt. and thus large grain size. The invention produces a thermally-stable and fine-grained standard, e.g. TlCl possessing grain size 40 nm., and which will withstand 20 mins. at up to 20 degrees C. without grain growth.