We report a comprehensive study on influence of oxygen partial pressure on NiO thin films grown on glass substrates in a combined argon and oxygen ambience by reactive dc magnetron sputtering. In this present article, we have discussed the dependence of oxygen pressure on structural, chemical, morphological, optical and electrical properties of the sputtered NiO films. Glancing angle x-ray diffraction reveals that the deposited films were polycrystalline in nature with FCC phase. The preferred orientation changes from (200) to (111) in a higher O₂ flow rate environment and an average particle size was estimated using Scherrer relation. The surface morphology of films was studied by using atomic force microscopy. The x-ray photoelectron spectroscopy analysis demonstrates the core level Ni 2p spectra over a range of 850 eV to 885 eV of binding energy and observed Ni 2p_3/2, Ni 2p_1/2 domains along with their satellite peaks. It infers the presence of both Ni⁺² and Ni⁺³ oxidation states in the sputtered films. Additionally, Raman spectroscopy was carried out to confirm the structural defects level and crystalline nature of the films. The optical results show that deposited films were semi-transparent and the evaluated optical band gap of the material lies in the range 3.36 eV to 3.52 eV. The extracted electrical properties infer either n-type or p-type conductivity depending on the processing conditions of the films.

In this article, we report a detailed study on the influence of sputter power on physical properties of the NiO films grown by DC magnetron sputtering. Structural studies carried out by Grazing Incidence X-ray diffraction (XRD) reveals the polycrystalline nature of the films with FCC phase. The crystallographic orientation (111) plane followed by (200), (220), and (311) plane were evident from the XRD spectra. The average crystallites sizes were estimated from the spectra, and the values were compared using three different plots such as Scherrer, Williamson–Hall and size–strain plot. The surface morphology was carried out by atomic force microscopy. The deposited samples show semitransparent behavior in the visible region and the estimated band gap increased from 2.70 to 3.34 eV with an increase in sputter power. Furthermore, X-ray photoelectron spectroscopy (XPS) core-level Ni2p spectra were deconvoluted and the observed $${\text{Ni}}2{\text{p}}_{{{\text{3/2}}}}$$Ni 2 p 3/2 , $${\text{Ni}}2{\text{p}}_{{1/2}}$$Ni 2 p 1 / 2 domain along with their satellite’s peaks were analyzed. Most importantly, XPS quantification data and Raman spectra confirm the presence of both $${\rm{Ni}}^{2+}$$Ni 2 + and $${\rm{Ni}}^{3+}$$Ni 3 + states in the NiO films. The electrical properties carried at room temperature revealed that the resistivity of the film significantly increased and a mobility of ~ 84 $${\rm{cm}}^{2}{\rm{V}}^{-1}{s}^{-1}$$cm 2 V - 1 s - 1 was obtained.

We investigated the influence of 10% substitution of rare-earth (RE) elements on the crystallographic, transport, and magnetic properties of La_0.67–x RE _x Ca_0.33MnO₃(RE = Nd, Sm, and Gd, x = 0.0, 0.1) manganite perovskite compounds. The bulk polycrystalline samples were synthesized using solid-state reaction method. The phase purity and crystal structure of studied samples were confirmed by room temperature X-ray diffraction followed by the Rietveld refinement analysis. A high temperature insulator to low temperature metal phase transition is observed in electrical transport measurement. We observed an enhancement in the temperature coefficient of resistance (TCR) and magnetoresistance (MR) by partially substituting La with RE ions. The maximum TCR ≈ 22% and MR ≈ 96% are observed in Gd doped sample. The magnetic transition temperature, T _c , decreases from ∼254 K for the pristine sample to about ∼165 K for the Gd-doped sample. Our analysis of electrical and thermal transport data shows that the Small Polaron Hopping (SPH) is predominant at high temperatures conduction mechanism, whereas at low temperatures mechanism is dominated by electron-magnon scattering. The high temperature insulator paramagnetic phase to low temperature metallic ferromagnetic phase transitions are also observed in thermal conductivity and specific heat.

Herein, fabrication and characterisation of p-NiO/Al Schottky barrier diodes have been realised by dc reactive magnetron sputtering. In addition, effect of post-annealing temperature was studied. A detailed investigation on the physical properties of the NiO thin films was carried out using structural, morphological, optical, and spectroscopic characterisation tools. The metal–semiconductor interface behaviour has been analysed by current–voltage characterisation by implementing the Thermionic emission and Chueng model. The fabricated diode rectification ratio of 10³ has been recorded at $$\pm 3V$$± 3 V , and barrier height varied from 0.53 to 1.10 eV as a function of annealed treatment. A space charge-limited conduction mechanism and tunnelling through the interface trap density of p-NiO/Al Schottky diodes were explained by power law characteristics. Furthermore, we have evaluated the Schottky device's electrical characteristics through the ac measurements which include capacitance densities, dielectric constants, tangent loss, AC conductivity, and Nyquist plots. The present work could provide a better understanding and insight into the p-NiO/Al Schottky junction.

Herein, we report on the post-annealing temperature effect on the transport behavior of p-CuO/Al Schottky barrier diodes. In addition, the transformation of phase from Cu₄O₃ to CuO phase was studied. Copper oxide thin films were grown on soda lime glass substrates, and post-annealing temperature's influence on the films’ structural, chemical, morphological, and electrical characteristics was comprehensively examined. X-ray diffraction study revealed the development of polycrystalline tenorite phase (CuO) on annealing. Raman analysis also confirmed the formation of the tenorite phase (CuO) at higher annealing temperatures (400 °C and 500 °C). XPS study revealed the occurrence of the Cu₄O₃ phase for room temperature deposited sample and CuO phase at the higher annealing temperature. Using current–voltage analysis, the Chueng model, and the thermoelectric emission model, the Schottky behavior between the metal and semiconductor were investigated. The fabricated diode showed a rectification ratio of 10³ at ± 2 V, with the barrier height ranging from 0.84 to 1.12 eV due to different annealing treatments. The attributes of the power law were employed to elucidate space charge-limited conduction and the process of tunneling across the density of interface traps in p-CuO/Al Schottky diodes. This study provides valuable insights into the behavior of the p-CuO/Al Schottky junction, enhancing our understanding of its characteristics.