Investigating the optical, electronic, magnetic properties and DFT of NiO films prepared using RF sputtering with various argon pressures
Date
28.04.2023Author
Hopoğlu, HicretKaya, Dogan
Maslov, Mikhail M.
Kaya, Savas
Demir, İlkay
Altuntaş, İsmail
Ungan, Fatih
Akyol, Mustafa
Ekicibil, Ahmet
Şenadım, Tüzemen Ebru
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Show full item recordAbstract
In this study, we investigated the structural, optical, magnetic, and conductive properties of nickel oxide (NiO)
films on glass substrates deposited using Radio Frequency (RF) magnetron sputtering with varying Ar gas
pressure and thickness. X-ray diffraction and Rietveld refinement analysis confirmed a cubic crystal structure and
showed that the lattice parameters and the d(111)-space increased from 4.0559 Å to 4.2712 Å and from 2.3208 Å
to 2.4582 Å, respectively, due to increased Ar pressure during deposition. Scanning electron microscopy and
atomic force microscopy were used to determine the cross-sectional and surface topology of the NiO films, which
exhibited uniform and homogeneous growth with an average spherical size of 54.28 ± 0.33 nm. The optical
bandgap values of the films were calculated to be between 3.26 and 3.65 eV, increasing with pressure. Hall
measurements confirmed the p-type semiconductor nature of the films with an average sheet carrier density of
1010 cm����� 2. The films exhibited soft magnetic properties, with a maximum Hc and Ms of 178.5 Oe and 5.82 emu/
cm3 for 246 nm NiO film, respectively. Density functional theory (DFT) calculations confirmed the experimental
results for both single to five layers NiO films and bulk NiO formations. The refined energy gap value was found
to be 3.2 eV by the DFT calculation. The films produced at room temperature were found to be stable and
reproducible, making them suitable as p-type materials for device construction.