Williamson-Hall and Size-strain plot based micro-structural analysis and evaluation of elastic properties of Dy³⁺ substituted Co-Zn nano-spinels

Abstract

Polycrystalline Co-Zn nanoferrites doped with rare earth Dy3+ ions having general chemical formula Co0.9Zn0.2DyxFe1.9-xO4 (x = 0.0, 0.015, 0.03, 0.045 and 0.06) were synthesized via sol-gel auto-combustion route. Powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform Infrared Spectra (FTIR) were performed to investigate the structural, microstructral, surface morphology and elastic properties. Well indexed XRD patterns confirm the phase purity and cubic spinel structure of the samples. Fractional doping of Dy3+ ions shifts the Bragg’s lines slightly towards the lower angles which in turn increases the lattice lengths from 8.3795 Å to 8.3834 Å. The strain induced in the crystal lattice was estimated by using Williamson-Hall and Size – Strain Plot methods. Both methods confirm that the tensile type strain was induced in the crystal lattice and increases with the substitution of Dy3+ ions. Surface morphology of the samples was studied by using SEM images which reveals that the grains are almost spherical in nature and the size obtained is analogues with XRD results. FTIR spectra shows the existence of two main absorption bands within the wave number range 388 – 586 cm−1 which confirm the characteristics of spinel ferrites. Elastic properties were estimated by using FTIR data. Elastic moduli and Debye temperature increases with the substitution of Dy3+ ions which are interpreted on the basis of interatomic bondings.

Optical and photoluminescence properties of trivalent rare earth ions doped LiMgPO4

“…The materials typically undergo strain owing to the presence of crystallographic defects and the higher ionic radius of RE 3+ -ions [32]. The study utilized a Williamsons-Hall (W-H) equation with various peaks to assess the microstructural parameters including average crystallite size and micro-strain of all aforementioned materials.…”