Size effect on properties of varistors made from zinc oxide nanoparticles through low temperature spark plasma sintering

Léna Saint Macary (1) , Myrtil L Kahn (1) , Claude Estournès (2, 3) , Pierre Fau (1) , David Trémouilles , Marise Bafleur (3) , Philippe Renaud , Bruno Chaudret (1)

1 LCC - Laboratoire de chimie de coordination
2 CIRIMAT - Centre interuniversitaire de recherche et d'ingenierie des matériaux
3 LAAS - Laboratoire d'analyse et d'architecture des systèmes

Conditions for the elaboration of nanostructured varistors by spark plasma sintering (SPS) are investigated, using 8-nm zinc oxide nanoparticles synthesized following an organometallic approach. A binary system constituted of zinc oxide and bismuth oxide nanoparticles is used for this purpose. It is synthesized at roomtemperature in an organic solution through the hydrolysis of dicyclohexylzinc and bismuth acetate precursors. Sintering of this material is performed by SPS at various temperatures and dwell times. The determination of the microstructure and the chemical composition of the as-prepared ceramics are based on scanning electron microscopy and X-ray diffraction analysis. The nonlinear electrical characteristics are evidenced by current–voltage measurements. The breakdown voltage of these nanostructured varistors strongly depends on grain sizes. The results show that nanostructured varistors are obtained by SPS at sintering temperatures ranging from 550 to 600 8C.

Mots clés: Nanoparticles; Organometallic materials; park plasma intering; Varistors; Zinc oxide

Domaines: Matériaux

Léna Saint Macary, Myrtil L Kahn, Claude Estournès, Pierre Fau, David Trémouilles, et al.. Size effect on properties of varistors made from zinc oxide nanoparticles through low temperature spark plasma sintering. Advanced Functional Materials, 2009, 19 (11), pp.1775-1783. ⟨10.1002/adfm.200801067⟩. ⟨hal-00383348v1⟩