Structural and magnetic properties of Dy3+-doped BaTiO3 nanorods: A study of the tetragonal-to-cubic phase transition and emergent diluted magnetism

Abstract

Nanocrystalline pristine BaTiO<inf>3</inf> (BTO) and Dy3+-doped BaTiO<inf>3</inf> (Dy-BTO) nanorods were synthesized via the hydrothermal method. Structural and compositional analyses using XRD, TEM, XPS, and Raman spectroscopy confirmed the successful incorporation of Dy3+ ions into the BaTiO₃ lattice, with the formation of pure-phase nanorods. Dy3+ doping induced a structural phase transition from the tetragonal (P4mm) to the cubic (Pm3¯m) symmetry, as verified by XRD and Raman results. XPS analysis further revealed that the valence mismatch between the dopant Dy3+ and the host Ba2+ leads to the creation of Ti3+ ions and oxygen vacancies in Dy-BTO. Magnetic characterization through M–H measurements showed that Dy-BTO exhibits an unsaturated hysteresis loop, indicating the coexistence of paramagnetic (PM) and ferromagnetic (FM) phases, while pristine BTO displays a combination of diamagnetic (DM) and FM behavior. The magnetic interactions were quantitatively analyzed using the bound magnetic polaron (BMP) model, which suggests that the formation of Dy3+–V<inf>o</inf>–Dy3+ and Ti3+–V<inf>o</inf>–Dy3+ centers plays a crucial role in mediating and stabilizing FM ordering. These findings highlight Dy-BTO nanorods as promising candidates for spintronic applications. © 2025 Elsevier B.V.