Paramagnetic behaviour of silver nanoparticles generated by decomposition of silver oxalate

Hoa Le Trong (1, 2) , Kateryna Kiryukhina (2, 3) , Michel Gougeon (2) , Valérie Baco-Carles (2) , Frédéric Courtade (3) , Sophie Dareys (3) , Philippe Tailhades (2)

1 VNU-HCM - Vietnam National University, Ho Chi Minh City / Đại học Quốc gia TP. Hồ Chí Minh
2 CIRIMAT - Centre interuniversitaire de recherche et d'ingenierie des matériaux
3 CNES - Centre National d'Études Spatiales [Toulouse]

Silver oxalate Ag2C2O4, was already proposed for soldering applications, due to the formation when it is decomposed by a heat treatment, of highly sinterable silver nanoparticles. When slowly decomposed at low temperature (125 °C), the oxalate leads however to silver nanoparticles isolated from each other. As soon as these nanoparticles are formed, the magnetic susceptibility at room temperature increases from -3.14 10-7 emu.Oe-1.g-1 (silver oxalate) up to -1.92 10-7 emu.Oe-1.g-1 (metallic silver). At the end of the oxalate decomposition, the conventional diamagnetic behaviour of bulk silver, is observed from room temperature to 80 K. A diamagnetic-paramagnetic transition is however revealed below 80 K leading at 2 K, to silver nanoparticles with a positive magnetic susceptibility. This original behaviour, compared to the one of bulk silver, can be ascribed to the nanometric size of the metallic particles.

Mots clés: Silver oxalate; Silver nanoparticles; Paramagnetic silver; Oxalate decomposition; Nanocrystalline metal; Soldering

Domaines: Mécanique des matériaux [physics.class-ph]; Mécanique des solides [physics.class-ph]

Hoa Le Trong, Kateryna Kiryukhina, Michel Gougeon, Valérie Baco-Carles, Frédéric Courtade, et al.. Paramagnetic behaviour of silver nanoparticles generated by decomposition of silver oxalate. Solid State Sciences, 2017, vol. 69, pp. 44-49. ⟨10.1016/j.solidstatesciences.2017.05.009⟩. ⟨hal-01750400⟩