Effect of rare earth doping on the vibrational spectra of spinel Mn-Cr ferrite. (January 2018)

• Record Type: Journal Article
• Authors: Abdellatif, M.H.; Azab, A.A.; Salerno, M.
• Is Part Of: Materials research bulletin. Volume 97(2018)
• Page Start: 260
• Page End: 264
• Publication Date: 2018-01
• Subjects: Spinel structure -- Ferrite -- Rare earths -- Raman -- FTIR -- Ball milling; Materials -- Periodicals; Crystal growth -- Periodicals; Matériaux -- Périodiques; Cristaux -- Croissance -- Périodiques; Crystal growth; Materials; Periodicals; 620.11
• DOI: 10.1016/j.materresbull.2017.09.012
• Languages: English
• ISSNs: 0025-5408

Abstract

Graphical abstract: Highlights: Doping spinel ferrite with large rare earth ions affects the structure. The crystal field is distorted to preserve the physical symmetry of spinel lattice. The distortion in the lattice can be physical or compensated. Compensation of the distortion is a reason for Raman and IR peak shifts. New vibrational bands appear such as optical magnon coupling. Abstract: We prepared ferrites doped with different rare earth elements (La, Ce, Sm, Gd, Dy) by ball-milling the oxides of these metals and using double sintering technique. The so-prepared ferrites have been first characterized by X-ray diffraction. We investigated the effect of rare earth doping on the spinel structure. The substituted rare earth ions, which are larger than the pristine ions, cause a different amount of distortion in the octahedral and tetrahedral sites of the ferrite lattice, which is correlated with their different size. This distortion in the spinel lattice induces different polarization effects when the materials are hit by incident electromagnetic radiation. The vibrational response of the prepared materials has been investigated by means of Raman and FTIR spectroscopy. The collected spectra show the fundamental modes as predicted by factor group theory. The dependency of Raman shift on rare earth doping affects the optical and magnetic properties of the material.