Entangled exchange-spring magnetic structure driven by surface magnetic symmetry-breaking in Cr2O3 nanoparticles

Bulk Cr2O3 is an antiferromagnetic oxide that exhibits the magneto-electric effect at room temperature, with neither spontaneous magnetization nor net electric polarization. These physical properties stem from a subtle competition...

Optical, Structural, Morphological Properties of Chromium (III) Oxide Nanostructure Synthesized Using Spray Pyrolysis Technique

Nanostructure of chromium oxide (Cr2O3-NPs) with rhombohedral structure were successfully prepared by spray pyrolysis technique using Aqueous solution of Chromium (III) chloride CrCl3 as solution. The films were deposited on glass substrates heated to 450°C using X-ray diffraction (XRD) shows the nature of polycrystalline samples. The calculated lattice constant value for the grown Cr2O3 nanostructures is a = b = 4.959 Å & c = 13.594 Å and the average crystallize size (46.3-55.6) nm calculated from diffraction peaks, Spectral analysis revealed FTIR peak characteristic vibrations of Cr-O Extended and Two sharp peaks present at 630 and 578 cm-1 attributed to Cr-O “stretching modes”, are clear evidence of the presence of crystalline Cr2O3. The energy band gap (3.4 eV) for the chromium oxide nanostructures was measured using the UV-VIS-NIR Optical Spectrophotometer. It was found that by scanning electron microscopy (SEM) and image results, there is a large amount of nanostructure with an average crystal size of 46.3-55.6 nm, which indicates that our synthesis process is a successful method for preparing Cr2O3 nanoparticles.

Optimization and Characterization of Bioactive Biocomposite Film Based on Orange Peel Incorporated With Gum Arabic Reinforced by Cr2O3 Nanoparticles

In this paper, the effect of adding gum Arabic at levels of 0-5%, and chromium oxide nanoparticles (Cr2O3 NPs) at levels of 0-3%, are investigated on orange peel-based films. The obtained results reveal a significant increase (p<0.05) in water vapor permeability, weight loss, tensile strength, and Young's modulus of film samples by increasing the percentage of both gum and nanoparticles. Moreover, the addition of gum Arabic and Cr2O3 NPs decreases the thickness, water-solubility, L*, a*, b* indexes while increasing the elongation to the breaking point. Furthermore, the moisture content of the film samples was decreased by the addition of nanoparticles, however, the addition of gum Arabic increased this parameter. The obtained results from the morphology of the samples indicated an increase in both roughness and cracks by increasing the percentage of nanoparticles as well as creating a smooth surface with the addition of gum Arabic. Besides, the results of FTIR revealed no new peak in the prepared samples, as compared to the control sample. The results of XRD indicated that the addition of gum Arabic and nanoparticles simultaneously caused the formation of new crystals and increasing the crystallinity of the films. Based on TGA results, the thermal stability of films containing the nanoparticles increased, as compared to the control sample. In the meantime, the addition of gum and nanoparticles increased the antimicrobial properties of the film samples, as compared to the control. Overall, those films created by the orange peel including gum Arabic and Cr2O3 NPs could enhance the mechanical properties and water vapor permeability of the samples.