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Iron artifacts undergo complex corrosion processes, depending on the burial environment. Understanding the formation mechanism of corrosion products is crucial for preservation of artifacts and helps design strategies for future iron artifacts protection. Mössbauer spectroscopy was primarily utilized in this work to analyze the corrosion products formed on iron artifacts. The corrosion products were identified as consisting of goethite, lepidocrocite, magnetite, and maghemite. Low-temperature Mössbauer spectroscopy was performed for the accurate identification and quantitative analysis of superparamagnetic iron corrosion products. The results indicated that the surface corrosion products mainly consist of goethite and superparamagnetic goethite, with small amounts of lepidocrocite, magnetite, and/or maghemite. A cross-sectional analysis of the corrosion layers on an artifact was performed to better understand the corrosion products and their formation mechanisms. The products formed in different sections (metal, intermediate, and surface) of the corrosion layers on the iron artifact were identified, and a corrosion mechanism was proposed. The intermediate layer adjacent to the metal contains magnetite, maghemite, and lepidocrocite. The results presented in this study provide a deeper understanding of the iron corrosion process, laying a solid foundation for the development of an effective strategy for preserving iron artifacts.

Banded iron formations (BIFs), significant iron ore deposits formed approximately 2.3 billion years ago under low-oxygen conditions, have recently gained attention as potential geological sources for evaluating hydrogen (H₂) production. BIFs are characterized by high concentrations of iron oxide (20 to 40 wt.%) and low Fe 3 ⁺/Fe tot ratios, representing a major source of ferrous iron on Earth. This study investigates the mineralogical and geochemical characteristics of iron ore samples from the Wugang and Hengyang BIFs in China using X-ray diffraction (XRD) and Mössbauer spectroscopy to examine H 2 generation potential. XRD analysis and microscopic observations showed that the magnetite and hematite are the primary ore minerals in BIFs in China Craton. Mössbauer spectroscopic results provided the quantified information on the fractions of each iron species in varying minerals. Particularly, the Fe 3+ tetrahedral sites and octahedral sites occupied by both Fe 2+ and Fe 3+ in magnetite and Fe 3+ octahedral sites in hematite were determined. We estimated H₂ production potential by calculating the relative fraction of Fe 2+ in magnetite relative to total number of iron atoms in the bulk samples from the Mössbauer results. The pyroxene-bearing BIF in Wugang (P-BIF) contains magnetite predominantly (~30.4 wt%), and the fraction of Fe 2+ in magnetite is ~26%. Based on the quantified values, the maximum potential for H 2 generation from P-BIF in Wugang could be ~630 mmol H₂/kg rock. Due to the variation of mineralogical composition depending on the types and locations of occurrence of BIF, the H 2 generation potential also varies. For example, contrast to P-BIF in Wugang, the hematite-rich BIF from Hengyang, containing ~6.0 wt% of magnetite, showed significantly lower Fe 2+ fraction in magnetite (~5%), resulting in low H 2 potential (~120 mmol H₂/kg rock). This study presents that a prevalence of magnetite in BIFs has considerable potential for H₂ production due to low Fe 3+ /Fe tot , suggesting that the magnetite-rich iron ore can be effectively utilized as the source of stimulated hydrogen production. The current results also highlight that the Mössbauer spectroscopy is essential to provide the database of relative fractions for each iron species in BIFs, which allows us to estimate the quantity of H 2 released from BIFs.

This study identified the cause of the minor lifetime component and the effect of the polymer adhesive in the positron source on positron annihilation lifetime spectroscopy. Three types of positron sources with different concentrations of the polymer adhesive were compared using nickel (Ni) and adhesive specimens. The unnecessary components of the positron lifetime due to the polymer adhesive could be eliminated by a source correction of approximately 20.8%. The results showed that minimizing the amount of polymer adhesive in the positron source is recommended, or a detailed source correction is required, to analyze the positron lifetimes accurately.

This study aims to enhance the amorphous formation ability and magnetic properties that are crucial for the production of high-quality nanocrystalline alloys. The structural, thermal, and magnetic characteristics of the alloy ribbons were analyzed through a systematic adjustment of Nb content, and, including Nb, significantly improved the amorphous formation ability and thermal stability of the alloy, which is vital for nanocrystalline production. By varying the Nb content within Fe85-xSi2B8P4Cu1Nbx (x = 0.0, 0.5, 1.0, and 1.5), we explored finer adjustments to achieve homogeneous amorphousness during the melt spinning process. Careful control over the Nb content facilitated the production of amorphous ribbons with consistent homogeneity, which was critical for the subsequent fabrication of nanocrystalline structures through heat treatment. As a result, the amorphous ribbon of Fe85.5Si2B8P4Cu1Nb0.5 showed a low coercivity of 7 A/m. The heat treatment showed a remarkably high saturation magnetic flux density of 1.94 T. Additionally, the grain size (D) decreased as the Nb content increased, with D values ranging from 25.09 nm to 24.29 nm, as calculated by the Scherrer formula. Mössbauer spectroscopy confirmed the formation of nanocrystalline and residual amorphous phases. The hyperfine magnetic field values (Beff) decreased from 25.7 T to 24.7 T in the amorphous samples and reached 33.0 T in the nanocrystalline phases. This study highlights Nb’s positive impact on thermal stability and amorphous formation capacity in Fe-Si-B-P-Cu alloys, culminating in the successful fabrication of nanocrystalline ribbons with superior structural and magnetic properties.

The study analyzes the black color factors of black-burnished pottery excavated from the Pungnap Fortress and the Seokchon Tomb during the Hanseong period of the Baekje Kingdom. The current hypothesis surrounding the pottery’s black color factors suggests the use of magnetite, manganese oxide, and carbon. To compare the results of the black pottery, red pottery was used as the control group. To identify these black color factors, each hypothesis was investigated using several spectroscopic techniques. However, it was difficult to detect sufficient magnetite and manganese oxide on the surface of the black pottery to account for its black color. In contrast, a larger amount of carbon was located on the surface and core of the black pottery compared to the red pottery. These results indicate that the black factors can be credibly attributed to carbon rather than to magnetite or manganese oxide. The firing temperature of the black-burnished pottery was estimated from the mineral composition based on X-ray diffraction, and the firing atmosphere was deduced from the redox conditions based on the reduction index from Mössbauer spectroscopy. In addition, seven pieces of pottery excavated from Gunsu-ri Temple Site and Buyeo Ancient Tomb from the Sabi period of Baekje were investigated and compared the five pieces of pottery from the Hanseong period. Although the results were based on a limited number of potteries, various firing temperatures and redox atmosphere for pottery from the Hanseong and Sabi periods were carefully proposed.

Antianemic medicament ferrous gluconate, ferrous fumarate, and a Dynabi tablet with a basic iron bearing ingredient were studied with the use of Mössbauer spectroscopy. Room temperature spectra of ferrous gluconate gave clear evidence that the two phases of iron were present: ferrous (Fe2+) as a major one with a contribution at and above 91 a.u.% and ferric (Fe3+) whose contribution was found to be ~9 a.u.%. In the case of ferrous fumarate, a single phase was measured corresponding to ferrous (Fe2+) state. A Dynabi tablet consists of ferrous fumarate and ferrous fumarate. The ferric phase in ferrous gluconate is able to be reached about ~3.6 a.u.% in a tablet.

Fe- and Cu-doped ZnO nanorods have been synthesized by a novel process employing a hydrolysis of metal powders. Zn, Fe, and Cu nanopowders were used as starting materials and incorporated into distilled water. The solution was refluxed at 60°C for 24 h to obtain the precipitates from the hydrolysis of Zn and dopants (Cu and Fe). The TEM results for ZnO with and without metal doping showed that the produced powders had a rod-like shape. The rod shape was attributable to the zinc oxide from the hydrolysis of Zn. With an increasing doping content, the UV-vis spectra were shifted to a long wavelength and this result indicates that the band gap was changed by the metal doping. The values of phenol degrading Fe- and Cu-doped ZnO by a solar simulator were measured to be 60 and 75%, respectively.

The method and conditions of Ni plating were optimized to maximize the output of a betavoltaic battery using radioactive 63Ni. The difference of the short circuit currents between the pre- and postdeposition of 63Ni on the PN junction was 90 nA at the I-V characteristics. It is suspected that the beta rays emitted from 63Ni did not deeply penetrate into the PN junction due to a Ni seed layer with a thickness of 500 Å. To increase the penetration of the beta rays, electroless Ni plating was carried out on the PN junction without a seed layer. To establish the electroless coating conditions for 63Ni, nonradioactive Ni was deposited onto a Si wafer without flaws on the surface. This process can be applied for electroless Ni plating on a PN junction semiconductor using radioactive 63Ni in further studies.

The nickel (Ni), and carbon coated nickel (Ni@C) nanoparticles were synthesized by levitaional gas condensation (LGC) methods using a micron powder feeding (MPF) system. Both metal and carbon coated metal nano powders include a magnetic ordered phase. The synthesis by LGC yields spherical particles with a large coercivity. The abnormal initial magnetization curve for Ni indicates a non-collinear magnetic structure between the core and surface layer of the particles. The carbon coated particles had a core structure diameter at and below 10 nm and were covered by 2-3 nm thin carbon layers. The hysteresis loop of the as-prepared Ni@Cs materials with unsaturated magnetization shows a superparamagnetic state at room temperature.