King Saud University
Riyadh, Riyadh Province | Saudi Arabia
Dr. Khalid Mujasam Batoo, received his Ph.D in Applied physics from, Aligarh Muslim University, India. He is at present Associate Professor at King Abdullah Institute for Nanotechnology, King Saud University, Riyadh, Saudi Arabia since 2010. As an invited speaker, he has delivered many talks on nanotechnology and its applications in various countries such as Egypt, UAE, Saudi Arabia, Hong Kong, USA, China, Turkey, Bangladesh, Greece, India, etc. His international acclaims comprise of an academic excellence award from Dover publications New York, U.S.A., Junior Research fellowship Award from Inter University Accelerator Center, New Delhi, India 2007, Speakers award in NANO-15 held at KSR Institutes, Tirchendode, Tamil Nadu, India, ICNA-III-2016 Award from South Valley University, Egypt, young Faculty Award-2016 by Venus International Research Foundation, India, speakers award in Kingdom Plastic Summit 2017, Riyadh, Saudi Arabia, outstanding scientist in nanotechnology award by Venus International Foundation 2017, Chennai India. As principal investigator, he has completed two international research Projects funded by the National Plan For Science and Technology and King Abdul Aziz City for Science and Technology, Kingdom of Saudi Arabia (3.5 Million Saudi Riyal). He has completed one project funded by King Abdul Aziz City of Science and Technology, and 3 projects by Deanship of Research group King Saud University, Saudi Arabia. He has authored more than 100 research papers published in peer reviewed Journals of International commendation and conference papers. He is currently serving as the editorial board member of more than 13 international Journals. His research interests include magnetic nanomaterials, nanocomposite materials, Thin Films, Graphene materials, Solar cells and study of Structural, morphological ad transport electrical and magnetic properties and there with an emphasis on understanding micro/ nano structural influences on functional properties.
Primary Affiliation: King Saud University - Riyadh, Riyadh Province , Saudi Arabia
Journal of Magnetism and Magnetic Materials
The Er/Sm-substituted nickel ferrite and Sm-substituted cobalt ferrite nanomaterials were synthesized via citrate-gel autocombustion technique. The diffraction pattern revealed the formation of cubic spinel structure. In addition, the structural parameters such as lattice constant (a), average crystallite size (D) and X-ray density (ρx) were also evaluated. The surface morphology was analyzed using field emission scanning electron microscope (FESEM) and transmission electron microscopes (TEM). Besides, the low temperature magnetic properties were studied using magnetization versus temperature (M−T) & magnetic field (M−H) curves. The obtained results attributed that the NiSm0.1Fe1.9O4 (NSF) and NiEr0.1Fe1.9O4 (NEF) samples exhibited the superparamagnetic property pertaining almost zero value of coercivity (Hc) and remanence (Mr) at 5 K & 300 K. Moreover, the superparamagnetic property was evidenced by zero-field cooled (ZFC) and field cooled (FC) curves. Interestingly, the CoSm0.1Fe1.9O4 (CSF) sample performed the soft magnetic behavior with increase of temperature from 5 to 300 K by possessing certain numerical values of Hc and Mr.
Journal of Magnetism and Magnetic Materials
This paper highlights the experimental study of Ce3+ ions doped M-type hexaferrite Sr1−xCexFe12O19 (0.00 ≤ x ≤ 0.30) prepared by adopting the conventional ceramic process. The M-type hexagonal structure is confirmed in the X-ray diffraction measurements. There were two phases recognized for the magnetic powders with varying Ce content, one in-between x = 0.00 to 0.20 as a single magneto plumbite segment and the other at x ≥ 0.20 as a second phase or the so called α-Fe2O3 phase. The micrographs of the sintered magnets depicted hexagonal crystal shapes. For magnetic properties a systematic study was done on the room temperature B–H hysteresis measurements. The estimated remanence value first increases with x in the range of x = 0.00 to 0.15 and then showed a decrease at x ≥ 0.15. Besides, the intrinsic coercivity (Hcj) and magnetic induction coercivity (Hcb) show decreasing-increasing character while maximum energy product (BHmax) and ratio Hk/Hcj demonstrate increasing-decreasing character in the Ce doping range x of x ≤ 0.15 and x > 0.15 respectively.
The rare earth gadolinium (Gd3+) ions doped nanocrystalline cobalt-zinc ferrites chemically formulated as Co0.7Zn0.3GdxFe2-xO4 (x = 0–0.1) were synthetically prepared by sol-gel self-ignition process. The characterization the ferrite samples was performed by powder x-ray diffraction method. The analysis of x-ray diffractograms (XRD) reveals formation of cubic spinel phase without presence of any ambiguity peak. The calculated particle size of the samples varies between 18 nm and 28 nm showing decreasing trend with Gd3+ doping. The distribution of cations analysed from XRD data propose occupancy of tetrahedral (A)-site by Zn2+ and Fe3+ while octahedral [B]-site by Fe3+, Gd3+ and Co2+ ions. The morphology of the ferrites was studied from the SEM images. The nanocrystalline particles arranged in layers with presence of porous structure can be observed in the SEM images. The particles of spherical shape with mean diameter of 27 nm were observed in the TEM image. The confirmation of peaks revealed by XRD data was performed by SAED image of the ferrite. The fringe width of the lattice fringe in HRTEM confirms formation of pure spinel phase in the Gd3+ doped Co-Zn ferrite. The VSM data analysed for measurement of magnetic parameters viz. coercivity, retentivity and saturation magnetization. The compositional variation of magnetization with Gd3+ doping reveals spin canting due to non-collinearity of spins of (A) and [B]-site. The Y-K angles calculated from cation distribution data were increased with Gd3+ doping due to spin canting. The variation of coercivity with Gd3+ doping was in accordance with the variation of anisotropy constant. The frequency variation of real part (μ') and imaginary part (μ") of μ* (complex permeability) were studied as a function of Gd3+ composition and frequency. The permeability was influenced by magnetic and structural parameters. The domain wall movement and spin rotations were responsible for magnetism in the ferrites. Previous article in issueNext article in issue Keywords Nanocrystalline ferritesGadolinium dopingMagnetizationMagnetic permeability
In the present work, Mn0.5Zn0.5CuxFe2-xO4 (x = 0.0, 0.1, 0.2 & 0.3) nanoferrites have been synthesized via solution combustion technique. X-ray diffraction (XRD), vibrating sample magnetometer (VSM) and Mössbauer spectroscopy techniques have been employed to explore the structural, cation distribution and magnetic behaviour of the synthesized nanoferrites. Rietveld refined XRD confirmed the cubic spinel phase of the nanoferrites with Fd3m space group. A reduction in particle size (51-40 nm) has been observed with the addition of copper ions. The Nelson–Riley plots have been used to estimate the lattice parameter and the same has been observed to increase (8.40–8.46 Å) with the increasing substitution of copper content. The addition of copper ions has been observed to decrease the saturation magnetization (0.89–0.76 emu/g) and magnetic hyperfine field. Magnetization method has been used to predict the distribution of cations. The distribution of cations has been further utilized to investigate various structural parameters.
The present study has a dual aim of supporting magnetic nanoparticles over the nanolayers of LDHs and designing two-dimensional magnetic nano-nets of cobalt ferrite. In this trend, nanoparticles of CoFe2O4 were prepared and supported by Co-Fe LDH through urea hydrolysis. The nanolayered structures of Co-Fe LDH were confirmed by X-ray diffraction, energy-dispersive X-ray spectrometry, FT-IR spectra, thermal analyses, and transmission electron microscopy. In addition, they indicated that 13.2% CoFe2O4 were supported over Co-Fe LDH. Transformation of the nanolayered structures of Co-Fe LDH to nano-nets was achieved by the catalytic effect of the supported CoFe2O4 nanoparticles through solvent thermal technique. X-ray diffraction patterns and transmission electron microscopy images confirmed the transformation of the supported Co-Fe LDH to nano-nets of cobalt ferrite. In order to indicate the effect of the LDH for designing the nano-nets, nanoparticles of cobalt ferrite were prepared by the same technique without LDH. The magnetic behavior of the nano-nets and the supported Co-Fe LDH were measured and compared with the nanoparticles through vibrating sample magnetometer technique. The magnetic parameters indicated that the prepared nano-nets have ferromagnetic behavior and high coercivity. However, the prepared nanoparticles revealed a superparamagnetic state and low coercivity. The experimental results concluded that the incorporation of nanoparticles with nanowires into nano-net structures has been found to be an efficient way to improve their magnetic properties and prevent their agglomerations. Finally, layered double hydroxides are an important source for constructing magnetic nanolayered structures and nano-nets
Journal of Alloys and Compounds
Co2Z-type hexa nanoferrites of the series Ba3-XSrXCo2Fe24O41 (where x = 0, 0.5, 1.0, 1.5 and 2.0) are synthesized by sol-gel auto combustion method. The effects of Sr2+ substitution for Ba2+ and optimized synthesis conditions are reported using the structural, magnetic and Mössbauer study. The X-ray diffraction (XRD) analysis and transmission electron microscopy (TEM) along with the selected area electron diffraction (SAED) clearly indicate the formation of a single-phased Z-type hexagonal nanoferrites with P63/mmc space group. The hysteresis curves obtained by vibrating sample magnetometer (VSM) at room temperature displayed the typical characteristics of magnetically soft materials indicating the decrease in coercivity with the increase in Sr2+ concentration in synthesized hexa nanoferrites, which are validated by the room temperature Mössbauer spectra with least-squares fit sextets of six distinguishable sites (A: 4fIV, B: 4fIV*, C: 12kVI*, D: 4fVI* + 4eIV, E: 12kVI and F: 2dV + 2aVI + 4fVI + 4eVI). Selection of Sr2+ dopant and sol-gel auto combustion soft chemical route are the leading ways to control the coercivity of Co2Z-type hexa nanoferrites.
Chinese Journal of Physics
M-type hexaferrites with Co2+ and Ni2+ions substituting for Fe3+ ions (Ca0.30Sr0.35La0.35Fe12.0−x(Co0.5Ni0.5)xO19, 0.0 ≤ x ≤ 1.0) were prepared by the traditional solid state method. X-ray diffractometer (XRD), field emission scanning electron microscopy (FE-SEM), physical property measurement system-vibrating sample magnetometer (PPMS-VSM) have been employed to study the microstructures and magnetic properties of hexaferrites. XRD patterns showed that the single magnetoplumbite phase is obtained if Co–Ni content (x) ≤ 0.4 and impurity phases are observed in the structure when Co–Ni content (x) ≥ 0.4. FE-SEM micrographs showed that the hexaferrites with hexagonal platelet-like grains is obtained. The saturation magnetization (Ms), remanent magnetization (Mr), Mr/Ms ratio, magneton number (nB), coercivity (Hc), magnetic anisotropy field (Ha) and first anisotropy constant (K1) decrease with increasing Co–Ni content (x) from 0.0 to 1.0. And our reported results with tunable Hc and Mr can be used for recording applications.
In the present work, optimised polyaniline–cadmium ferrite (PANI– CdFe2O4) composite was prepared by chemical polymerization method. Comparative structural and morphological studies of PANI, CdFe2O4 and the composite were carried out by Fourier transform infrared spectroscopy, X-ray diffraction study and scanning electron microscopy. Highly crystalline nature of the composite composed of nanosized particles was confirmed by transmission electron microscopy studies. The dielectric loss tangent at room temperature for PANI, CdFe2O4 and the composite were investigated in the frequency range 50 Hz–5 MHz. The Maxwell–Wagner type polarisation in PANI and CdFe2O4 was confirmed by the decrease in their dielectric loss tangents with increasing frequency. But for the composite, a loss tangent peak due to relaxation losses implying resonance between hopping frequency of charge carriers and applied alternating current electric field was obtained. Debye type single relaxation in PANI and the distribution of relaxation in the composite were confirmed by their respective complex plane impedance
BMC Complement Altern Med 2017 Dec 29;17(1):554. Epub 2017 Dec 29.
Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan.
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Nanoscale Res Lett 2012 Sep 18;7(1):511. Epub 2012 Sep 18.
King Abdullah Institute for Nanotechnology, King Saud University, P,O, Box 2460, Riyadh, 1151, Saudi Arabia.
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Nanoscale Res Lett 2012 Feb 8;7:112. Epub 2012 Feb 8.
King Abdullah Institute for Nanotechnology, King Saud University, PO Box 2460, Riyadh, 11451, Kingdom of Saudi Arabia.
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Nanoscale Res Lett 2011 Aug 18;6(1):499. Epub 2011 Aug 18.
King Abdullah Institute for Nanotechnology, King Saud University, Riyadh, 11451, Saudi Arabia.
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J Nanosci Nanotechnol 2011 Jan;11(1):396-401
School of Nano and Advanced Materials Engineering, Changwon National University, 9 Sarim dong, Changwon-641-773, Republic of Korea.
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Journal of Inorganic and Organometallic Polymers and Materials
In this study, a novel Ba1−xCuxFe12O19 (0.5 ≤ x) nano-hexaferrites were prepared by a simple and cost-effective sol–gel auto-combustion method using barium nitrates, iron nitrate, copper (II) acetate monohydrate and citric acid, and its structural, optical properties and hyperfine interactions were reported. Structural properties were analyzed through XRD (X-ray diffraction), Scanning electron microscopy (SEM), and TEM (Transmission electron microscopy), while percent diffuse reflectance spectroscopy (DRS) and Mössbauer spectrometer were used for analyzing the optical and magnetic properties of the resultant products. The observed Mössbauer studies proved the ferromagnetic nature of nanoparticles (NPs) samples. The crystallite size (XRD) varies in a range of (23.30–35.12) nm. The direct optical energy band gap (E g ) of all samples were calculated by Tauc plots where the E g values are found in a small range of 1.97–2.15 eV. The experimental evidences signify the promising use of newly prepared nano-hexaferrites in the development of materials in various industrial devices and far better than the conventional available hexaferrites materials.