TRANSMISSION ELECTRON MICROSCOPY OF THIN ([200 A) THERMALLY FORMED ZRO2 FILMS

An attempt has been made to determine the mode of ZrO2 formation on bulk zirconium at 300 °C in 760 Torr of dry oxygen. Zirconia films less than 2000 Å in thickness were chemically removed from their substrates and studied in transmission in an electron microscope. An interpretation of the Zr/ZrO2 epitaxy on a zirconium (0001) plane is given. All films contained oxide crystallites which ranged in size from the detection limit of the imaging technique (≈ 30 Å) to 250 Å. In some instances, up to 30 or 40 % of the projected film area lacked long range crystal order (i.e., more than a few atom spacings). © 1968.