Dr. IJEH RUFUS OBIOMA
Publication Title Magnetic and optical properties of electrodeposited nanospherical copper doped nickel oxide thin films
Publication Type journal
Publisher Elsevier
Paper Link https://doi.org/10.1016/j.physe.2019.05.013
Publication Authors Rufus O. Ijeh, Assumpta C. Nwanya, Agnes C. Nkele, Itani G. Madiba, Z. Khumal, A.K.H. Bashir, R.U. Osuji, M. Maaza, Fabian I. Ezema,
Year Published 2019-05-09
Abstract Copper doped nickel oxide (NiO:Cu) thin films were synthesized via electrodeposition technique. X-ray diffraction, Scanning Electron Microscope, UV–visible spectroscopy, Vibrating Sample Magnetometer techniques and electrochemical analysis were utilized for the study of the structural, morphological, optical, magnetic and cyclic voltammogram properties respectively of both undoped and doped NiO thin films. The crystallographic studies of the undoped and doped NiO thin films showed that they are polycrystalline with cubic structure.
Surface morphology of both the undoped and doped thin films showed nanocrystalline grains with spherical shaped particles. The optical studies showed a decrease in band gap energy from 3.34 eV to 3.32 eV and finally to 3.20 eV for the undoped, 2% and 3% respectively. The refractive index peaked between 2.60 and 2.65 while the calculated extinction coefficient values of the doped thin films have significant variation in the visible and NIR range. The studies of magnetization saturation values were found to be 1.52E-4 and 2.29E-4 for 2% and 3% doped respectively with low remanence values. Electrochemical studies revealed good cyclic voltammograms of the deposited films. These values indicate that the electrodeposited Cu doped NiO thin films are good candidates for magnetic applications.
Publication Title Zinc ferrite nanoparticles capped with Gongronema latifolium for moderate hyperthermia applications
Publication Type journal
Publisher Springer
Paper Link https://doi.org/10.1007/s00339-021-05244-8
Publication Authors Onah A. Onyedikachi, Samson O. Aisida, Ada Agbogu, Ijeh Rufus, Ishaq Ahmad,• M. Maaza Fabian I. Ezema
Year Published 2022-01-07
Abstract Zinc Ferrite Nanoparticles were synthesized using the eco-friendly green synthesis protocol. Gongronema Latifolium (GL) leaf extract as a potential reducing and capping agent to influence the properties of ZFNPs for effective hyperthermia application is emplaced in this work. Characterizations techniques such as X-rays diffractometer (XRD), scanning electron microscope (SEM), Fourier transforms infrared (FTIR) spectroscopy, UV–visible spectroscopy and vibrating sample magnetometer were used to determine the properties of the samples. The SEM showed spherical morphology of the samples, XRD spectra revealed the crystallinity with a maximum crystallite size of 30.6 nm, the absorbance surface plasmon resonance peak from the UV result falls within the visible range. The FTIR result showed the various functional group responsible for the reduction of the sample. The VSM confirmed the superparamagnetic nature of the sample. The saturation magnetization increases as the concentration of GL increases. The hyperthermia application properties investigated revealed good specific loss power, which decreases from 207.8 to 105.3 W/g as the concentration of GL increases. Notably, the synthesized nanoparticles have the potential for hyperthermia application in cancer therapy.
Publication Title Tailoring the Microstructural, Optical, and Magnetic Properties of MgFe2O4 Nanoparticles Capped Polyethylene Glycol Through a Bio-Inspired Method
Publication Type journal
Publisher Taylor & Francis Group, LLC
Publication Authors Abeeha Batool, Samson O. Aisida, Ijeh Rufus, Arshad Mahmood, Ishaq Ahmad, Ting-kai Zhao & Fabian I. Ezema
Year Published 2022-09-12
Abstract Ferrite materials have found applications in numerous areas, chiefly for hyperthermia in cancer therapy, targeted drug delivery and photodegradation. In this work, magnesium ferrite nanoparticles (MgFNPs) were formulated using polyethylene glycol (PEG) as a capping agent to tailor the properties and heighten the biocompatibility for suitable biomedical applications. The characterization results clearly showed the effect of PEG tailoring the properties of the formulated MgFNPs. A crystallite size with a value between 16 and 91nm was determined from the X-ray diffraction (XRD) analysis. The scanning electron microscopy (SEM) analysis showed particles of spherical shape for all the samples and the particle size was enhanced as the concentration of PEG increased. The vibrating sample magnetometer (VSM) showed a ferromagnetic nature for the samples with reduced saturation magnetization as the concentration of PEG was increased. The PEG concentration heightened the properties of the sample and can be highly optimized for suitable biomedical applications.
Publication Title Thermal annealing on the EDS and Optical properties of TiO2/CuO Core-Shell Thin Films
Publication Type journal
Publisher ECRTD-UK https://www.eajournals.org/
Paper Link https://doi.org/10.37745/ejms.2014
Publication Authors Daniel U. Onah, Peter E. Agbo, Mary O. Nwodo, Rufus O. Ijeh, Edwin H. Uguru and Omeje, Conelius U.
Year Published 2021-02-12
Abstract Studies of thermal annealing on the energy dispersive spectrometer (EDS) analysis and some optical properties of TiO2/CuO core-shell thin films were carried out in the visible, infrared and UV regions. In this study, the optical properties such as reflectance, absorption and extinction coefficients in relation to the annealing temperatures were particularly investigated. Results of this study showed that: the films are crystalline and contained no impurities as EDS analysis indicated, the as–deposited thin film has the lowest values of reflectance ranging from 5–12% within 400–1100nm (visible –NIR) regions. Low reflectance values of the films improved their qualities as photovoltaic materials. The sample annealed at 473K has the highest value of absorption coefficient in the UV (0.29–0.35??m) region. The films are good materials for UV sensors. The variations of the reflectance, absorption and extinction coefficients of the films with the annealing temperatures cannot be said to be in; a direct or any defined proportion.
Publication Title Influence of temperature on energy band gap and other properties of undoped and cadmium doped manganese sulphide (MnS:Cd) synthesized for photovoltaic and optoelectronic application
Publication Type journal
Publisher Asian Journal of Nanoscience and Materials
Paper Link DOI: 10.26655/AJNANOMAT.2022.2.1
Publication Authors Imosobomeh L, Ikhioyaa, Ijeh Rufus, Nwamaka Ifeyinwa Akpu
Year Published 2022-03-18
Abstract The synthesis of undoped and ccadmium doped Manganese Sulphide (MnS:Cd) films consists of; Manganese (ii) acetate tetrahydrate (C4H6MnO4.4H2O), cadmium sulphate (CdSO4), and Thiourea SC(NH2)2. The electrochemical deposition (ECD) method was adopted in this research. The samples' morphological, structural, elemental, optical, and thickness were studied using appropriate techniques. The films exhibited uniform distribution of spherical balls from the morphological studies while the structural features showed crystalline peaks at (100), (002), (101, (200)) and (203) planes at 2? (22.66, 27.77, 32.44, 36.25 and 42.80) angels. The elemental composition analysis of the deposited samples confirmed the elements deposited in the samples. For optical studies, we observed enhanced characteristics upon doping. The absorbance, transmittance, and reflectance increase as the incident radiation wavelength increases with an increase in bandgap energy from 1.8 eV–3.6 eV. The synthesized films find potential application in photovoltaic and optoelectronics. The material thickness obtained was seen to vary directly proportionally with the energy band gap values. More so, the addition of Cd to pure MnS and increase in deposition temperature for MnS:Cd increased the thickness of the material.
Publication Title Optical, electrical and magnetic properties of copper doped electrodeposited MoO3 thin films
Publication Type journal
Publisher Elsevier
Publication Authors Rufus O. Ijeh , Assumpta C. Nwanya, , Agnes C. Nkele , Itani G. Madiba , A.K.H. Bashir , A.B.C. Ekwealor, R.U. Osujib, M. Maaza , Fabian Ezema
Year Published 2020-01-16
Abstract Copper-doped MoO3 thin films were prepared via electrodeposition technique. The techniques adopted for investigating the structural, optical, electrical and magnetic properties of both undoped and copper-doped MoO3
thin films include X-ray diffractometry, UV–visible spectroscopy, four-point probe and vibrating sample magnetometry respectively. Nanocrystalline homogenous grains with polycrystalline orthorhombic (?-MoO3) nature
were obtained. The optical plots recorded decreased band gap energy from 3.44 eV to 3.27 eV, magnetic studies
showed ferromagnetic properties of the doped samples while the electrical study revealed the highest conductivity of 1.5 ?cm?1
. Doping with Cu has the potentiality of increasing the conductivity of MoO3 thereby
enhancing its application in photocells.
1. Introduction
Molybdenum trioxide (MoO3) is an important transition metal oxide
that has attracted the attention of researchers. It portrays a high degree
of fascinating optical and electrical properties as a result of its notable
technological applications [1–6]. MoO3 is a wide n-type semiconductor
(Eg? = 3.1 eV) with high ionic conductivity as a result of oxygen vacancies [7]. The three stages of molybdenum trioxide include monoclinic (?-MoO3), hexagonal (h-MoO3) and orthorhombic (?-MoO3) with
the later having the highest stability [8]. The layered structure makes
its' absorption of light readily and uniformly available for responses in
electrochromic and photochromic displays [4]. These properties enhance its applications in smart windows [9], light emitting diodes [10],
optical switching coatings [11], gas sensors [12,13] and lithium batteries [2,7]. Recently due to the interest in spintronic devices, a lot of
researches are focused on doping non-magnetic semiconductors with Li,
Cu, Mn in order to produce semiconductors with ferromagnetic properties. Doping causes electrons to become unpaired and enables researchers to exploit the properties of materials in order to modulate the
transport of electrons and holes in semiconductors [14,15]. It is obvious
t
Publication Title Annealing optimization of graphitized Co3O4@CuO@NiO composite electrodes for supercapacitor applications
Publication Type journal
Publisher wileyonlinelibrary.com/journal/
Paper Link https://doi.org/10.1002/est2.34
Publication Authors Raphael M. Obodo, Sylvester M. Mbam, David C. Iwueke, Muhamed Ramzan ,Rufus Ijeh, Ishaq Ahmad, Maalik Maaza,Fabian I. Ezema
Year Published 2022-04-11
Abstract
Publication Title Structural, optical and magnetic properties of Cu-doped ZrO2 films synthesized by electrodeposition method
Publication Type journal
Publisher Elsevier
Publication Authors Rufus O. Ijeh, Cyril O. Ugwuoke , Ernest B. Ugwu , Samson O. Aisida , Fabian I. Ezema
Year Published 2021-11-08
Abstract The electrodeposition technique was used to synthesize copper-doped ZrO2 thin film. Different characterization
technique such as vibrating sample magnetometry, UV–visible spectroscopy, scanning electron microscope, and
X-ray diffractometry were used to study the magnetic, optical, surface morphology, and structural properties of
the thin films. The Uniform nanocrystalline grains without cracks, and of various sizes were obtained. The optical
studies showed a decrease in energy band gap from 4.1 eV to 3.9 eV. The magnetic studies revealed that the
doped samples have unique ferromagnetic ordering, this could be due to the increase in grain size. The 2% and
4% doped samples are saturated around 4.51 × 10? 4 emu/g and 4.70 × 10? 4 emu/g at coercive field of 274.54
and 274.96 respectively.