Room temperature growth of half-metallic Fe3O4 thin films on polycarbonate by reactive sputtering: heterostructures for flexible spintronics

Abstract

Nowadays, there is a huge demand of bendable/stretchable electronic devices because of their remarkable capabilities. With such an aim and inclination towards flexible spintronics devices, half-metallic nanocrystalline Fe3O4 thin films with various thicknesses are grown on flexible polycarbonate (PC) substrates by reactive sputtering at room temperature. The structural analysis reveals that as the deposition time increases from ∼165 s to ∼1335 s, the thickness of the film also increases from 50 nm to 400 nm with the size of the grain from ∼12 nm to ∼32 nm, respectively. The X-ray photoelectron spectroscopy (XPS) shows that the films grown on PC substrates are the pure form of Fe3O4 nanostructures. The electrical and magnetic characteristics are studied to illustrate the furtherance of the original belongings of Fe3O4. The Verwey transition temperature (Tv) of ∼127 K, Ms value of ∼317 emu/cm3 and MR -8.3% under H ∥ Film plane below 60 kOe at 300 K for 200 nm thick Fe3O4 film on PC substrate were observed. Additionally, several bending experiments are executed to confirm the retention and adjustability of these properties for such heterostructures. These remarkable results show that Fe3O4/PC heterostructures can be a promising applicant for flexible spintronics.