Magnetic properties ofIn2O3containingFe3O4nanoparticles

Abstract

Films of Fe-doped In 2 O 3 that were deliberately fabricated so they contained Fe 3 O 4 nanoparticles were deposited on sapphire substrates by pulsed laser deposition at low oxygen pressure. The concentration of Fe was varied between 1% and 5%, and the effect of including 5% of Sn and vacuum annealing were also investigated. Structural analysis indicated a high concentration of Fe 3 O 4 nanoparticles that caused substantial values of the coercive field at room temperature. Transport measurements indicated that the films were metallic, and an anomalous Hall effect was observed for the sample with 5% of Fe. The concentration of nanoparticles was reduced dramatically by the inclusion of 5% of Sn. Magnetic circular dichroism spectra taken in field and at remanence were analyzed to show that the samples had a magnetically polarized defect band located below the conduction band as well as magnetic Fe 3 O 4 nanoparticles. The signal from the defect states near the band edge was enhanced by increasing the number of carriers by either including Sn or by annealing in vacuum.

Characterization of the iron oxide phases formed during the synthesis of core–shell FexOy@C nanoparticles modified with Ag

“…The structural and magnetic properties of these NPs were described in [14] as it was mentioned above. The spectra of all these samples demonstrate the same shape very similar to the magnetite, Fe 3 O 4 , MCD spectrum shape known in literature [37][38][39][40].…”

Relevance of the Preparation of the Target for PLD on the Magnetic Properties of Films of Iron-Doped Indium Oxide

“…An interesting comparison was made between the properties of PLD-ablated films of (InFe) 2 O 3 formed when the grinding was done mechanically compared with using hand grinding using a pestle and mortar. The Fe ions that were in the films that had been ablated from a target that had been formed using mechanical grinding were almost entirely present as a secondary phase of Fe 3 O 4 [10]. Essentially all the Fe ions were on In sites in films made using the exact same protocol of grinding and sintering but using hand grinding with a pestle and mortar [5].…”

“…However, there are also reports of Fe-doped In 2 O 3 thin films that contain magnetic nanoparticles of Fe 2 O 3 or Fe 3 O 4 [20,25,27]. The presence of the Fe 3 O 4 nanoparticles has been reported to enhance the room temperature magnetisation, magnetoresistance and a larger value of the coercive of~400 Oe [10].…”

“…Previous work has considered Fe 2 O 3 to be the obvious precursor to use with In 2 O 3 to generate a target for the PLD because it should generate a stoichiometric target [5,10,15,19,24,26]. It is well known that if a film is ablated from a target in a high vacuum, the film will contain less oxygen than the target because some oxygen is lost in the PLD process.…”