Infrared spectroscopic study of pulsed laser deposited Fe3O4 thin film on Si (111) substrate across Verwey transition temperature

Abstract

We present low-temperature infrared measurements of magnetite (Fe 3 O 4 ) thin films on Si (111) substrate across the Verwey transition temperature (T V ). The line parameters of the most intense t 1u mode observed in the Fourier transform infra red spectrum of the film is studied as a function of temperature. We observe that mode frequency increases abruptly at 130 K, and full width at half maxima of the mode increases abruptly at 113 K. The observations point out that structural transition may start earlier at 130 K than the actual Verwey transition (121 K) and that complete at 113 K. These results are consistent with the higher transition temperature as observed in resistivity and magnetization measurements.

Kinetics and intermediate phases in epitaxial growth of Fe3O4 films from deposition and thermal reduction

“…7(a). The Verwey transition temperature around 120 K is visible but not as clear as that in bulk, 10,12,13,48 consistent with the significant domain boundaries. To highlight the Verwey transition, we have calculated effective activation energy (𝐸 𝑎 𝑒𝑓𝑓 ) using the relation…”

“…8 The resistivity of Fe3O4 decreases when temperature increase, with a rapid change at TV  120 K, noted as the Verwey transition, which is often considered as a signature of the Fe3O4 phase. [9][10][11][12][13] Great efforts have been devoted to preparing epitaxial Fe3O4 thin films using pulsed laser depositions, with a variety of target materials to begin with, including metal Fe, 14 Fe3O4, 9,15-18 and Fe2O3. [9][10][11][12]19 The iron oxide phase and oxygen stoichiometry of the films are sensitive to the growth conditions, especially temperature and background gas pressure.…”

“…[9][10][11][12][13] Great efforts have been devoted to preparing epitaxial Fe3O4 thin films using pulsed laser depositions, with a variety of target materials to begin with, including metal Fe, 14 Fe3O4, 9,15-18 and Fe2O3. [9][10][11][12]19 The iron oxide phase and oxygen stoichiometry of the films are sensitive to the growth conditions, especially temperature and background gas pressure. 15 Therefore, thermodynamics and chemical reactions on the substrate are the key for the growth of Fe3O4 films, as also indicated by many studies on the transitions between iron oxide phases using surface characterizations.…”

Magnetism modulation of Fe/ZnO heterostructure by interface oxidation

“…5(a), after annealing, a peak located at 710.5 eV between and Fe þ2 , implying the formation of Fe 3 O 4 . [17][18][19] In the case of as-deposited 10 nm Fe/ZnO, as shown in Fig. 5(d), the pure Fe peak dominates with a shoulder of Fe-oxide in as-deposited sample.…”

Terahertz dielectric properties of Fe3O4 thin films deposited on Si (100) substrate

“…These films are selected in a way to get a landscape of σ 1 (ν) and ϵ 1 (ν) of Fe 3 O 4 /Si films with respect to film thickness, amount of Fe 3 O 4 to Fe 2 O 3 ratio, and/or Fe 2+ to Fe 3+ ratio. The details of the thin film preparation can be found elsewhere [20,23]. The structural characterization of the samples was performed with the help of x-ray diffraction (XRD) experiments using Cu-Kα radiation in Bragg-Brentano configuration.…”