Metallic oxide films ofSrRuO3deposited on (001)SrTiO3by pulsed laser deposition have been investigated by transmission electron microscopy (TEM) techniques. These films have a single crystalline structure with an extremely smooth surface. A TEM study of cross-sectional samples shows that the film grew epitaxially on the (001) surface of theSrTiO3substrate. The films grew along the [110] directions with an in-plane orientation relationship of eitherSrRuO3[1¯10]//SrTiO3[100] andSrRuO3[001]//SrTiO3[010], orSrRuO3[11¯0]//SrTiO3[010] andSrRuO3[001]//SrTiO3[100]. Domains with a rotation of 90° aroundSrRuO3[110] were observed in the dark-field image of plan-view samples. ©1998 American Institute of Physics.