  Recent observation of quantum transport phenomena of Weyl fermions has
brought much attention to 4d ferromagnetic perovskite SrRuO3 as a magnetic Weyl
semimetal. Besides, the hump-like Hall effect anomaly, which might have a
topological origin, has also been reported for this material. Here, we show
that the emergence of such phenomena is governed by the degree of scattering
determined by the defect density (Ru-deficiency- and/or interface-driven-defect
scattering) and measurement temperature (phonon scattering), where the former
is controlled by varying the growth conditions of the SrRuO3 films in molecular
beam epitaxy as well as the film thickness. The resulting electronic transport
properties can be classified into three categories: clean, intermediate, and
dirty regimes. The transport of Weyl fermions emerges in the clean regime,
whereas that of topologically trivial conduction electrons in the ferromagnetic
metal state prevail in the intermediate and dirty regimes. In the clean and
intermediate regimes, anomalous Hall resistivity obeys a scaling law
incorporating the intrinsic Karplus-Luttinger (Berry phase) and extrinsic
side-jump mechanisms. The hump-like Hall effect anomaly is observed only in the
dirty regime, which is contrary to the scaling law between anomalous Hall
resistivity and longitudinal resistivity. Hence, we conclude that this anomaly
is not inherent to the material and does not have a topological origin. We also
provide defect- and temperature-dependent transport phase diagrams of
stoichiometric SrRuO3 and Ru-deficient SrRu0.7O3 where the appearance of Weyl
fermions and hump-like Hall effect anomaly are mapped. These diagrams may serve
as a guideline for designing SrRu1-xO3-based spintronic and topological
electronic devices.
