Influence of Fe3+ by La3+ cations substitution on the crystallography and magnetic properties of yttrium iron garnet compound

Abstract

In the present study, we have investigated the influence of La3+ cations insertion on the crystallography, morphology, and magnetic properties of Y3Fe5-xLaxO12 compound, (x = 0.00 and 0.03) obtained by the sol-gel method. To confirm the Fe3+ by La3+ cations replacement and quantify the structural parameters, the Rietveld refinement method was used. The quantitative analysis confirmed that, the La3+ cations insertion in the YIG crystal structure affect significative the lattice constant, crystallite size, microstrain, sites occupancy, bond angles and distances. Room temperature Raman spectra also confirmed the YIG single phase structure. The spectra deconvolution pointed shifts for smaller wavenumber in the sample containing La3+ cations, specifically in the region between 400 and 800 cm−1, correlated with the octahedral and tetrahedral sites. The coral format morphology was confirmed by Scanning and Transmission Electron Microscopies. Lastly, room temperature magnetic measurements demonstrated that the La3+ cations insertion in the YIG crystal structure, provokes an increase in the saturation magnetization (Ms), remanent magnetization (Mr) and magnetocrystalline anisotropy (K1) of 24.8, 17.5, and 9.3%, respectively, respect to the values obtained for undoped YIG sample.