Growth structure of yttria-stabilized-zirconia films during off-normal ion-beam-assisted deposition

Abstract

Biaxially aligned YSZ thin films with strong [100] fiber texture were formed on a polycrystalline Ni-based alloy by off-normal ion-beam-assisted deposition. Growth structures were characterized by x-ray diffraction (XRD), transmission electron microscopy (TEM), atomic force microscopy (AFM), etc., and the alignment mechanism was discussed using a selective growth model. Peculiar structural evolution of the crystalline orientation was observed and its development was well described by an exponential equation. It was explained as a collaboration of an anisotropic growth condition and epitaxial crystallization. The [100] fiber texture was formed by columnar structures of diameter of 30 -100 nm, which were composed of 5-10 nm diameter crystallites. Very smooth surfaces were observed by AFM imaging with a roughness of 2-3 nm and a peculiar ripple structure. The origin of the azimuthal alignment was discussed with emphasis on the surface structure of YSZ films produced using ion-beam-assisted deposition (IBAD) and the etching rate measurements of (100) surfaces of YSZ single crystals.

YSZ buffer layers on large technical substrates

“…The surface of both films exhibits a characteristic ripple-structure that has its wave vector parallel to the projected direction of the assisting ion beam. This kind of surface morphology was observed by Iijima, too [7].…”

High temperature superconductor (HTS) wires and tapes

“…The reason for the prolonged process was the evolutionary nature of texture development in these materials (Iijima et al 1998). Biaxial texture develops through dominance of grains preferentially oriented with respect to the ion beam incidence direction.…”

“…In this process an excimer laser operating at 308 nm (XeCl) or 248 nm (KrF) is used to ablate a target made of a superconducting material and the plume is deposited on a hot substrate (Foltyn et al 2000a, Iijima et al 1998, Usoskin et al 2001. A major advantage of PLD is the ability to form a stoichiometric fi lm of nearly the same composition as the target.…”

Ion Beam Induced Growth Structure of Fluorite Type Oxide Films for Biaxially Textured htsc Coated Conductors

“…Biaxially aligned Yttria Stabilized Zirconia (YSZ) or MgO films formed by ion-beamassisted deposition (IBAD) are reliable template layers for Y-123 coated conductors [1][2][3][4]. However, intercalation of thin CeO 2 or Y 2 O 3 layers beneath Y-123 film is still effective to compensate lattice mismatch and prevent slight interdiffusion [5].…”