Impact of vanadium substitution on structural, magnetic, microwave absorption features and hyperfine interactions of SrCo hexaferrites

The Co-V co-substituted nano Sr-hexaferrite, Sr0.5Co0.5VxFe12-xO19 (0.00 & LE; x & LE; 0.08) (V & RARR;SrCo (0.00 & LE; x & LE; 0.08) NHFs), were manufactured by citrate combustion route. The microstructure, morphology, magnetic features, hyperfine interactions and oxidation state and chemical composition of products explained by XRD, SEM with EDX, HR-TEM, VSM, Mossbauer spectrometry, and XPS, respectively. The DXRD (Average crystallite size) of products were assessed via Scherrer formula as within the range of 37 and 83 nm. The hexagonal morphology and chemical composition of the products was presented by TEM, HR-TEM, SEM and EDX analyses. The XPS analysis provided both the composition and oxidation states of prepared NHFs. Mossbauer spectra showed that the s electron density around Fe3+ ions of all sites except 12k influenced V3+ content. The coercivity data in-dicates that all samples denote a magnetically hard material at both low and high temperatures. Ms, Mr and nB fluctuate with respect to dopant concentration and attain their highest magnitudes for the V & RARR;SrCo (x = 0.04) NHFs. A SQR of around 0.5 is achieved at each temperature, reflecting a relatively high large anisotropy field. The field-cooling (FC) curves of all samples yield a drop in magnetization with increasing temperature. Their irre-versibility temperature is detected to be beyond 325 K. Both M-H and M-T imply the ferrimagnetic behavior of different samples. Microwave properties were measured between 2 and 18 GHz as S11-S21 parameters. It demonstrated non-linear behavior of the microwave properties vs. V concentration. The origin of the reflection losses in NHVs can be explained by the dipole polarization processes.& COPY; 2023 Elsevier B.V. All rights reserved.

Automated summary

The microstructure, morphology, magnetic features, hyperfine interactions, and oxidation state and chemical composition of Co-V co-substituted nano Sr-hexaferrite were investigated. The average crystallite size of the products was found to be in the range of 37-83 nm. The hexagonal morphology and chemical composition were observed and analyzed. The magnetization, coercivity, and microwave properties of the samples were also studied.