C. Kawai et A. Yamakawa, CRYSTAL-GROWTH OF SILICON-NITRIDE WHISKERS THROUGH A VLS MECHANISM USING SIO2-AL2O3-Y2O3 OXIDES AS LIQUID-PHASE, Ceramics international, 24(2), 1998, pp. 135-138
Si3N4 whiskers were coated on Si3N4 whisker substrates through a VLS m
echanism using SiO2-Al2O3-Y2O3 oxides as liquid phases. Alpha-Si3N4 wh
iskers having diameters of 0.4 to 0.7 mu m were used as seeds. After t
he seed whiskers were coated with SiO2-Al2O3-Y2O3 oxides, the oxide-co
ated whiskers were heated at 1490 degrees C N-2 including gas species
generated by reacting amorphous Si3N4 and TiO2 powders. Resultantly, w
hisker-like products were newly formed on the seeds. The morphologies
of the resulting whisker growth on the seeds resembled rose-twigs and
centipedes with long legs. X-ray diffraction analysis indicated that t
he newly formed whiskers were beta-Si3N4. Droplets were observed on th
e tips of some whiskers. This suggested that the whisker growth procee
ded through a vapour-solid-liquid (VLS) mechanism. (C) 1997 Elsevier S
cience Ltd and Techna S.r.l.