Phase Evolution in La-Alloyed β-Ga₂O₃ Nanofibers: Experimental and DFT Simulation Insights

La-alloyed β-Ga₂O₃ nanofibers with varying La concentrations (0, 1, 5, and 10 at. %) are successfully synthesized using the electrospinning method to investigate the effects of incorporating La on phase formations. At La 1 at. % alloying, the polycrystalline β-Ga₂O₃ phase remains stable, indicating that this concentration is within its solubility limit. However, higher La alloying levels (5 and 10 at. %) lead to the formation of additional phases, including La₂O₃, Ga₃La₅, La₄Ga₂O₅, cubic La₂O₅, and orthorhombic LaGaO₃. Notably, when increasing the La concentration, the nonoxide metallic compound La₃Ga₅ is observed, likely due to enhanced Ga-La interactions. Density functional theory (DFT) simulations confirm that La₃Ga₅ has metallic properties, which could potentially improve the electrical performance of Ga₂O₃-based devices. Furthermore, DFT simulations predict the formation, phase stability, and structure of La-based precipitates, offering valuable insights into the alloying behavior and material properties of Ga₂O₃. These findings suggest possibilities for enhancing the functionality of Ga₂O₃ semiconductors in electronic applications.