Thermionic electron emission microscopy of metal-oxide multilayers on tungsten

Abstract

Thick (200-nm) layers of reactively sputtered BaO and Sc <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$_{2}$</tex> </formula> O <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$_{3}$</tex></formula> on tungsten foil are imaged with thermionic electron emission microscopy (ThEEM). The scandia films are observed to show what we have named the “window effect,” i.e., apparent electron transparency in the ThEEM image, showing the underlying structure of the polycrystalline W foil.