Structure, physical properties, and applications of SrRuO 3 thin films

${mathrm{SrRuO}}_{3}$ is endowed with three remarkable features. First, it is a moderately correlated material that exhibits several novel physical properties; second, it permits the epitaxial growth of essentially single-crystal films; and third, because it is a good conductor, it has attracted interest as a conducting layer in epitaxial heterostructures with a variety of functional oxides. In this review, the present state of knowledge of ${mathrm{SrRuO}}_{3}$ thin films is summarized. Their role as a model system for studying magnetism and electron transport characterized by intermediate electron correlation and large magnetocrystalline anisotropy is demonstrated. The materials science of ${mathrm{SrRuO}}_{3}$ thin film growth is reviewed, and its relationship to electronic, magnetic, and other physical properties is discussed. Finally, it is argued that, despite all that has been learned, a comprehensive understanding of ${mathrm{SrRuO}}_{3}$ is still lacking and challenges remain.