Y. Yuan, J. Pan/Journal of Crystal Growth 193(1998)585-591 Flow of hydrogen(mWm Fig 4. Growth of hedgehog-like whiskers in the carbon rich regons. Flow rate of titanium tetrachloride (m Um in) Flow rate of methane( mWmin) Fig 3. The effects of vapor flow rates on the diameters of the TiC whiskers obtained at 1125C, 75 min. (a)The effects of hydrogen flow rate on the diameters, TiCl4 flow 50 ml min-I, methane flow rate=85 ml min-I.(b)The 500nm effects of TiCl+ flow rate on the diameters, hydrogen flow rate= 350 ml min-1. methane flow 85 ml min low ha e 5 o m mia ne Tic fe w te d 50 me m:in rogen the i scmacchnag ismtron micrograph of Tic whiskers grown by some carbon on nickel substrate prior to the forma- of the TiC whiskers have spherical liquid droplets tion reaction of the Tic whisker, and found that the the inherent characteristic of the vls mechanism TiC whiskers with a high yield grew hedgehog-like on their tips(see Fig. 5). The EDS analysis shows in the carbon rich regions, as shown in Fig 4. The that apart from titanium, nickel is also found in TiC whiskers grown by the VLs mechanism are these spherical tips, but not in whisker roots. Ac- experimentally verified in this experiment as most cording to the vLs mechanism, a binary Ni-TiFig. 3. The effects of vapor flow rates on the diameters of the TiC whiskers obtained at 1125°C, 75 min. (a) The effects of hydrogen flow rate on the diameters, TiCl4 flow rate"50 ml min~1, methane flow rate"85 ml min~1. (b) The effects of TiCl4 flow rate on the diameters, hydrogen flow rate"350 ml min~1, methane flow rate"85 ml min~1. (c) The effects of methane flow rate on the diameters, hydrogen flow rate"350 ml min~1, TiCl4 flow rate"50 ml min~1. Fig. 4. Growth of hedgehog-like whiskers in the carbon rich regions. Fig. 5. Scanning electron micrograph of TiC whiskers grown by the VLS mechanism. some carbon on nickel substrate prior to the forma￾tion reaction of the TiC whisker, and found that the TiC whiskers with a high yield grew hedgehog-like in the carbon rich regions, as shown in Fig. 4. The TiC whiskers grown by the VLS mechanism are experimentally verified in this experiment as most of the TiC whiskers have spherical liquid droplets — the inherent characteristic of the VLS mechanism — on their tips (see Fig. 5). The EDS analysis shows that apart from titanium, nickel is also found in these spherical tips, but not in whisker roots. Ac￾cording to the VLS mechanism, a binary Ni—Ti 588 Y. Yuan, J. Pan / Journal of Crystal Growth 193 (1998) 585–591