Gamma-irradiation induced synthesis of Ag-decorated Mg2Si: ion beam analysis investigation for enhanced thermoelectric performance

Abstract

Abstract Enhancing the thermoelectric properties of Mg2Si materials remains a challenge in the field of energy conversion. This study aimed to investigate the effects of silver decoration on the structural, morphological, and thermoelectric properties of Mg2Si nanoparticles. Mg2Si materials underwent 6-h ball milling, followed by silver decoration using gamma irradiation and AgNO3. The resulting samples were characterized through XRD, SEM, TEM, EDX, RBS, and DSC techniques. Thermoelectric properties were also evaluated. XRD analysis revealed a single phase for pure Mg2Si and a 76:24 wt.% ratio of Mg2Si:Ag for (Mg2Si@Ag) the decorated sample. SEM showed agglomerated particles, while TEM identified nano-sized particles ranging from 10 to 70 nm. EDX and RBS confirmed the presence of an Ag coating several micrometers thick. DSC data indicated a reduction in the melting point of Mg2Si to 490 °C due to Ag decoration. The thermoelectric performance, including Seebeck coefficient, electrical resistivity, thermal conductivity, and figure of merit (ZT), was significantly impacted by the Ag decoration. Ag decoration markedly improved the thermoelectric properties of Mg2Si nanoparticles. The maximum ZT values achieved were 1.5 for Mg2Si@Ag and 0.42 for pure Mg2Si, demonstrating the potential of this approach for enhancing thermoelectric materials.

Keywords

• Ag decoration
• Gamma irradiation
• Single-phase
• Nanoparticle agglomerations
• Nano-optical and thermal band gaps