Mechanism of Self-Epitaxy in Buffer Layer for Coated Conductors

To elucidate the self-epitaxy mechanism of pulsed-laser deposition-CeO₂, a hypothetical relationship with the substrate was derived based on the ion-beam-assisted deposition layer-processing method: the smaller the misorientation angle, the larger the crystallite size. In-plane misorientation angle dependences of crystallite sizes of ion-beam-assisted deposition-MgO and LaMnO₃ as substrates for CeO₂ deposition, obtained using X-ray diffraction and transmission electron microscopy, indicated that the hypothesis is plausible. This relationship is regarded as a prerequisite for self-epitaxy because large crystallites with small strains would be energetically favorable when CeO₂ particles crystallize on them. Eventually, they will grow to dominant grains, which is a possible self-epitaxy mechanism.