Polycrystalline morphology and anomalous Hall effect in RF-sputtered Co2MnGa films

The Heusler compound Co2MnGa is a topological semimetal with intriguing electronic and magnetic properties, making it a promising candidate for spintronic applications. This study systematically investigates the effects of substrate temperature and radio frequency (RF) sputtering power on the structure, morphology, and anomalous Hall effect (AHE) in Co2MnGa thin films with the goal to uncover trends in growth–morphology–property relationships. Using x-ray diffraction line analysis, we identify variations in film orientation and crystallinity, revealing the emergence of high-index textures at specific growth conditions. Atomic force microscopy imaging provides insight into grain morphology and size distributions demonstrating a correlation between deposition parameters and film texture. Magnetotransport measurements show a strong dependence of AHE on growth conditions, exhibiting a nonmonotonic relationship with RF power and temperature. Despite significant variations in microstructure, a striking linear relationship between AHE and the zero-field slope of the Hall resistivity is observed, suggesting an underlying universal mechanism. These findings provide a foundation for investigating the complex interplay of Co2MnGa informing us broadly that the AHE is strongly tunable by morphology, while at the same time the critical field remains robust.