Effect of oxygen partial pressure on the density of antiphase boundaries in Fe3O4 thin films on Si(100)

Highlights: • Fe₃O₄ thin films grown at various $P_{O_2}$ on Si(100) by DC magnetron sputtering. • APBs have been probed using Raman, magnetization and electron-transport measurements. • Sharp Tv and low e-p coupling constant observed for higher $P_{O_2}$ grown thin film. Polycrystalline Fe₃O₄ thin films were grown on Si(100) substrate by reactive DC sputtering at different oxygen partial pressures $P_{O_2}$ for controlling the growth associated density of antiphase boundaries (APBs). The micro-Raman analyses were performed to study the structural and electronic properties in these films. The growth linked changes in the APBs density are probed by electron–phonon coupling strength (λ) and isothermal magnetization measurements. The estimated values of λ are found to vary from 0.39 to 0.56 with the increase in $P_{O_2}$ from 2.2 × 10⁻⁵ to 3.0 × 10⁻⁵ Torr, respectively. The saturation magnetization (saturation field) values are found to increase (decrease) from 394 (5.9) to 439 (3.0) emu/cm³ (kOe) with the increase in $P_{O_2}$. The sharp Verwey transition (∼120 K), low saturation field, high saturation magnetization and low value of λ (comparable to the bulk value ∼0.51) clearly affirm the negligible amount of APBs in the high oxygen partial pressure deposited thin films.