Structural Analysis and Temperature-Dependent Impedance Behavior of BiFeO₃ Nanoparticles for PV Application

2026-07-01T09:34:32+00:00

Silicon semiconductor remains the principal material for commercial PV (photovoltaic) cells. Alternative PV materials are being actively explored to reduce dependence on silicon-based PV cells and improve future cell performance. Bismuth ferrite (BiFeO₃, BFO) has attracted consideration as a lead-free multifunctional oxide material for PV applications because of its preferable bandgap of 2.0 to 2.7. In this work, BiFeO₃ nanoparticles were synthesized by the sol–gel method and annealed at 600 °C, and their structural, morphological and impedance characteristics were examined. X-ray diffraction (XRD) analysis confirmed the formation of crystalline BiFeO₃ nanoparticles, confirming the rhombohedral R3c phase, with prominent diffraction peaks around 31.8° and 32° (2θ). Field-emission scanning electron microscopy (FESEM) revealed the surface morphology and particle size of 138 nm of the synthesized nanoparticles. The impedance behavior of BiFeO₃ was further investigated through frequency-dependent impedance measurements at 100, 200 and 300 °C. The impedance response showed a clear dependence on frequency and temperature. At 100 °C, impedance decreased continuously with increasing frequency. However, at 200 and 300 °C, the impedance showed dual behavior, first increased and then decreased with frequency. The structural development, nanoparticle morphology and temperature-dependent impedance response show that sol–gel-synthesized BiFeO₃ nanoparticles may be useful for PV cells and related electronic devices.

Investigation of Corrosion Behavior of Mild Steel in Simulated Atmospheric Environments: A Review of Salinity Effects

2026-07-30T09:49:58+00:00

This review provides a systematic structural evaluation of the atmospheric corrosion mechanisms of low-carbon mild steel, focusing exclusively on the impacts of airborne marine salinity and localized chloride ion deposition. Structural steel elements located within maritime coastal environments undergo aggressive electrochemical deterioration driven by the high loading of windborne halide aerosols. This paper organizes and evaluates empirical data from standardized simulation configurations to isolate the chemical, thermodynamic, and microstructural consequences of chloride contamination on the structural iron matrix. Experimental data synthesis reveals that elevated chloride deposition rates up to 120 mg/m²/day shift uniform surface thinning to severe localized pitting, reaching a maximum measured pit depth of 0.85 mm. Under high salinity film concentrations of 3.5 wt.% NaCl, the thin-film solution conductivity increases drastically, pushing the electrochemical corrosion current density (I_corr) from a baseline of 1.2 µA/cm² up to 49.6 µA/cm². Long-term mineralogical phase analysis confirms that continuous marine chloride exposure alters the rust scale evolution, forcing the preferential crystallization of loose, unstable akaganeite (β-FeOOH) tunnel crystals until it reaches a dominant 68% share within 12 weeks. Consequently, high surface salt accumulation up to 100 mg/m² results in a dramatic increase in cumulative steel weight loss to 295 g/m², triggering extensive scale delamination and blistering. These quantitative outcomes provide crucial empirical benchmarks for selecting high-durability protective barriers and calculating accurate structural corrosion allowances within high-salinity marine boundary layers.

International Journal of Materials and Mechanical Structures Engineering

Structural Analysis and Temperature-Dependent Impedance Behavior of BiFeO₃ Nanoparticles for PV Application

Investigation of Corrosion Behavior of Mild Steel in Simulated Atmospheric Environments: A Review of Salinity Effects