Influence of indium substitution and microstructure changes on the magnetic properties evolution of Y3Fe5−xInxO12 (x = 0.0–0.4)

Abstract

The role of indium (In) substitution in the dynamics of ferrimagnetism, structure and microstructure of yttrium iron garnet (YIG) employing sintering temperature as a temporary agent of composition and microstructural changes was examined closely and reported in this study. The nanoparticles of YIG powder samples with various In content (x = 0.0, 0.1, 0.2, 0.3, 0.4) were prepared via the mechanical alloying (MA) technique. A brief, yet revealing characterization of the samples was carried out by using a transmission electron microscopy, X-ray diffraction, Raman spectroscopy and scanning electron microscopy to analyse the structural and morphological properties, whereas B-H hysteresis graph and LCR-meter were used to measure the magnetic and thermo-magnetic behaviour respectively. The X-ray diffraction analysis of the samples prepared via the MA indicates the formation of single phase YIG structure at much lower sintering temperature than that in the conventional ceramic technique. The lattice constant increases as In content increases which obeys Vegard's law due to the larger In3+ ions replacing the smaller Fe3+ ions. The grain size also increased with In content, indicating that the In3+ ion acts as a grain growth promoter. The saturation induction increased reaching about 699.1 G for x = 0.3 and decreased with further In substitution. Three stages of ordered magnetism formation were identified which attributed to development of crystallinity and larger grains for magnetic domain accommodation. The Curie temperature shows a decrement of 60 °C for In content changes from x = 0.0 to x = 0.4 due to weakening of superexchange interactions. Raman shifts from 268.1 to 272.2 cm−1 with increasing In content were observed due to stress developed in the YIG crystal structure. Possible mechanisms contribute to these properties are discussed in this paper.

Influence of La- and Al-Dopant Substitutions on Morphology and Magnetic Characteristics of High Temperature Yttrium Iron Garnet

“…The results show the variation of particles size in which the particle size of pure YIG is larger than Al-and La-doped YIG. This may be due to the non-uniformity of the force used while grinding the powders producing large particle size distribution [6]. The particles size determination plays an important role in ensuring the uniformity of grain growth.…”

“…The particles size determination plays an important role in ensuring the uniformity of grain growth. Large particle size distributions may contribute to an abnormal grain growth, thus declining the effectiveness of the magnetic properties of the soft ferrites [6]. The study of samples crystallinity was done twice which is before and after sintering process using XRD to examine the phase existence before and after sintering process and whether the single phase garnet is formed after sintering at high temperature.…”

Evolution of Magnetic Properties in Ferrites: Trends of Single- Sample and Multi-Sample Sintering

“…The shapes of the hysteresis loop are largely correlated with the microstructural features of the material, particularly the grains in the sample [34][35][36][37][38][39][40]. Besides, the disparities of the shapes also arise from the various grain shapes, grain sizes, compositions, strains, and imperfections present in the sample.…”

Magnetic and Microwave Properties of Polycrystalline Gadolinium Iron Garnet

“…In order to achieve extremely low microwave loss requirement, material selection and processing method are aspects to be scrutinized. Among type of ferrites, garnet-type ferrites are well-known low microwave loss materials due to their superior properties such as high resistivity, moderate permeability, and low eddy current loss [2]. Lately, yttrium iron garnet (YIG) ferrite has been extensively studied and chosen as the best candidate to be exploited as a passive microwave component.…”