Stability of nanovoids in amorphous Si3B3N 7

2019-09-11 19:48:36

stability low 2005 cm3 equals

责任者: Hannemann, A.;Schon, J.C.;Jansen, M. 单位: Max-Planck-Institut fur Festkorperforschung, D-70569 Stuttgart, Germany 来源出处: Philosophical Magazine,2005,85(23):2621-2639 摘要: The amorphous ceramic material a-Si3B3N7 possesses a rather low density ( approximately equals 1.9 g/cm3) compared with, for example, the weighted average of the crystalline binary compounds Si 3N4 and BN ( approximately equals 2.8 g/cm3). Our simulations show that nanosize cavities, which are created during synthesis via the sol-gel route, can survive for a very long time even at elevated temperatures (up to 1500 K), and are thus the most likely explanation for the low density of a-Si3B3N7. Furthermore, we find that, at low temperatures, the application of very high pressures exceeding 10 GPa should lead to a considerable irreversible densification of the material up to approximately equals 2.8 g/cm3. © 2005 Taylor and Francis Group Ltd. 关键词: Amorphous silicon;Nanostructured materials;Stability;Ceramic materials;Temperature distribution;Pressure effects;Densification;Nanovoids;Crystalline binary compounds