Elastic study and optical dispersion characterization of Fe-substituted cobalt aluminate nanoparticles

• Published in: Applied physics. A, Materials science & processing Materials science & processing, 2020-06, Vol.126 (6), Article 443
• Main Author: El-Said Bakeer, D.
• Format: Article
• Language: English
• Subjects: Applied physics; Bulk modulus; Characterization and Evaluation of Materials; Chemical precipitation; Cobalt aluminate; Condensed Matter Physics; Crystallites; Cubic lattice; Dielectric strength; Elastic properties; Ferric ions; Iron; Lattice parameters; Machines; Manufacturing; Materials science; Modulus of elasticity; Nanoparticles; Nanotechnology; Optical and Electronic Materials; Optical properties; Permittivity; Physics; Physics and Astronomy; Poisson's ratio; Porosity; Processes; Rigidity; Specific heat; Spectrum analysis; Stiffness; Substitutes; Surfaces and Interfaces; Theoretical density; Thin Films; Wave velocity
• ISSN: 0947-8396; 1432-0630
• DOI: 10.1007/s00339-020-03625-z

The point of this work is to study the impact of Fe 3+ ions substitution on the structural, elastic and optical properties of CoAl 2 O 4 nanoparticles. A series of CoAl 2− x Fe x O 4 nanoparticles, 0.00 ≤  x  ≤ 0.20, are prepared by chemical co-precipitation method. X-ray diffraction besides the FTIR examination affirms the forming of single-phase cubic spinel CoAl 2 O 4 for Fe 3+ -substituted samples. The lattice constant a is found to be increased with increasing Fe 3+ content obeying Vegard’s law. The dependence of theoretical density, porosity and crystallite size on Fe 3+ content x is discussed. FTIR spectral analysis is used to estimate the elastic moduli such as stiffness constant, Young’s modulus, rigidity modulus, bulk modulus, Poisson’s ratio, wave velocity and Debye temperature. The stiffness constants and Poisson’s ratio increase with the increase in Fe 3+ content due to the decrease in porosity and substitution process. The values of Young’s modulus, rigidity modulus and Debye temperature reduce with an increase in the Fe 3+ content, whereas the bulk modulus increases with x . The optical properties of CoAl 2– x Fe x O 4 nanoparticles are analyzed using UV–Vis spectrophotometer measurements in the spectral range of 200–1100 nm. Some of dispersion parameters are evaluated based on a single oscillator model, such as oscillator energy E o , dispersion energy E d , lattice dielectric constant ε l , the average value of oscillator strength, S O , and wavelength of single oscillator λ O . The most important result of the current work is the use of Fe 3+ ion substitution in CoAl 2 O 4 nanoparticles, which can be used to modify the elastic moduli, optical band gaps and dielectric constant.