• Review

    Gas Sensors Based on Magnetic Ferrite Materials: Influence of Rare-Earth Dopants Lanthanum and Dysprosium on Sensing Properties
    Deepapriya Subramaniyan, John David Rodney, Simon Edward Moulton, Byung Chul Kim
    Magnetic ferrites are spinel-structured transition-metal oxide-based nanoparticles that exhibit distinctive magnetic, electrical, and surface characteristics, rendering them highly promising materials for gas-sensing … + READ MORE
    Magnetic ferrites are spinel-structured transition-metal oxide-based nanoparticles that exhibit distinctive magnetic, electrical, and surface characteristics, rendering them highly promising materials for gas-sensing technologies. Rare-earth doping, particularly with lanthanum (La) and dysprosium (Dy), induces substantial alterations in crystal symmetry, electronic structure, defect chemistry, and magnetic behavior within the ferrite lattice. Such intrinsic modifications profoundly govern gas adsorption kinetics, surface reactivity, and charge-carrier transport, all of which are pivotal to achieving superior sensing performance. This review provides a rigorous and comprehensive evaluation of recent advances in La- and Dy-doped ferrite-based catalysts for gas sensors, with specific emphasis on synthesis strategies, structure-property correlations, sensing mechanisms, and key performance indicators. The analysis demonstrates that rare-earth incorporation improves sensitivity, selectivity, response stability, and thermal robustness through the generation of oxygen vacancies, modulation of grain-boundary characteristics, and enhancement of surface-active sites. The review finally concludes by outlining critical future research priorities and translational considerations for scalable, commercially viable sensor deployment. - COLLAPSE
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    27 April 2026

  • Research Paper

    Influence of Al3+ Ion Doping on the Microstructure and Magnetic Properties of CoFe2O4 Spinel Ferrite
    Tagreed Muslim Al-Saadi , Mariam Osama Abd Alkareem, Shaymaa Ahmed Kadhim
    In this work, AlxCo1-xFe2O4 nanoferrites (x = 0, 0.05, 0.10, 0.15, and 0.20) were synthesized … + READ MORE
    In this work, AlxCo1-xFe2O4 nanoferrites (x = 0, 0.05, 0.10, 0.15, and 0.20) were synthesized from metal nitrates using the sol-gel method. The objective of this study was to investigate how replacing cobalt ions (Co2+) with non-magnetic aluminum ions (Al3+) would affect the structural, morphological, and magnetic properties of this ferrite. The X-ray diffraction (XRD) results indicated that pure cubic spinel could be obtained in all samples. At the same time, the values of the crystal lattice constant and grain size varied slightly and irregularly with aluminum content. Field emission scanning electron microscopy (FESEM) images indicated a uniform distribution of grains in the undoped sample (x = 0) and that the incorporation of (Al3+) led to a small increase in average grain size as well as broadened grain size distribution. The purity of the samples and successful substitution were additionally verified by energy-dispersive X-ray spectroscopy (EDX) analysis. Vibrating Sample Magnetometry (VSM) measurements demonstrated that the saturation magnetization and remanence decreased with increasing Al3+ content, which was attributed to magnetic relaxation caused by substituting ferromagnetic Co2+ ions for non-magnetic Al3+ ions. Values of the remanent-to-saturation magnetization ratio (Mr/Ms) also indicate the presence of single-domain magnetic particles. The coercive field (Hc) showed a non-monotonic dependence, increasing with the low concentrations of aluminum but decreasing weakly, and hence is an effect of the competition between internal stresses and a decrease in crystal anisotropy. This work has shown that the magnetic properties of cobalt ferrite can be modulated by substitution with aluminum. - COLLAPSE
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    27 April 2026

  • Research Paper

    Sulfur Content Control in the Ladle Furnace Process through Controlling the Pre-desulfurization Time during the Bubbling and Powder Injection Process and Slag Composition in Ladle

    BAP 공정 시 예비 탈황 시간 조정과 Ladle 내 슬래그 조성 제어를 통한 LF 공정에서의 황 함량 제어

    Chel-Jong Yoo, Jae-Gwan Lee, Gwang-Su Kim, Dong-Geun Lee

    유철종, 이재관, 김광수, 이동근

    In the steelmaking process, particularly during the ladle furnace stage, the ability to control sulfur content in molten steel to 30 ppm … + READ MORE
    In the steelmaking process, particularly during the ladle furnace stage, the ability to control sulfur content in molten steel to 30 ppm is critical for specific steel grades. This study aims to achieve reliable sulfur control by regulating the slag composition through flux addition during the steelmaking process, and by conducting preliminary desulfurization via the bubbling and powder injection (BAP) process. The target steel had a composition of [C] 0.08-0.16, [Mn] 1.0-1.5, [P] ≤ 0.02, and [S] ≤ 0.003 wt%. During the converter tapping process, flux was added in amounts of 1,000 kg, 1,500 kg, and 2,000 kg. In the BAP process, top and bottom bubbling was applied for 3 min, 5 min, and 8 min, respectively, to evaluate the effectiveness of preliminary desulfurization. The results confirmed that increasing the amount of flux improved sulfur control performance in the ladle furnace process. Moreover, when the BAP bubbling time exceeded 5 min, the time required to control sulfur in the ladle furnace process was significantly reduced. This study demonstrates that, in order to effectively control sulfur during the ladle furnace stage, both appropriate flux addition and preliminary desulfurization through the BAP process are essential. - COLLAPSE
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    27 April 2026
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Journal Informaiton Korean Journal of Materials Research Korean Journal of Materials Research
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