Li 2 FeSiO 4 /C JOURNAL OF THE CHINESE CERAMIC SOCIETY. SiC TaC. SiC TaC. TaC SiC TaC

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1 Li 2 FeSiO 4 /C JOURNAL OF THE CHINESE CERAMIC SOCIETY 739 Vol. 40 No. 5 May 2012 SiC TaC ( ) (TaCl 5 ) (TEOS) (C 6 H 12 O 6 H 2 O) 450 C SiO 2 Ta 2 O SiC TaC X SiO 2 Ta 2 O 5 Si O Ta Si O Ta C TaC SiC SiC TaC 0.02 SiC TaC SiC TB332 A (2012) :40:35 Synthesis of SiC TaC Nanopowder with Hybrid Precursor via Carbonthermal Reduction LI Qing XIAO Hanning GAO Pengzhao GUO Wenming HU Jilin XIE Wen OUYANG Tangzhe (College of Materials Science and Engineering, Hunan University, Changsha , China) Abstract: A compound gel was firstly prepared with tantalum pentachloride (TaCl 5 ), tetraethoxysilane (TEOS) and glucose (C 6 H 12 O 6 H 2 O) as starting materials, and the gel was then calcined at 450 to obtain a C SiO 2 Ta 2 O 5 hybrid precursor. A nanopowder of SiC TaC was synthesized with the precusor via the carbonthermal reduction at The products were charaterized by using X-ray diffration, scanning electron microscope, energy dispersive. The results show that the amorphous SiO 2 and Ta 2 O 5 can be composed by Si O Ta bonding, and the evenly-distributed Si O Ta C long chain renders the solid structure of interpenetrating networks inside the hybrid precursor. TaC was obtained at <1 200, and SiC started to be synthesized at 1 400, and the whole reaction process could be fully completed at The nanopowder of SiC TaC presented distinct features at different mole ratios of tantalum to silicon. The particle size distribution of the powder appeared narrower at a mole ratio of tantalum to silicon of The morphology of SiC could vary from spherical nanoparticles into curve-shaped nanowires when the mole ratio increased. Key words: silicon carbide-tantalum carbide; nanopowder; sol gel; precursor; glucose; homogeneity (SiC) [1 3] (TaC) (TMC) [4 6] SiC TaC SiC TaC [7 8] TaC SiC [9 10] SiC TaC SiC TaC TiC/SiC [11] ZrC SiC [12] C/TaC SiC [13] SiC WC [14 15] (No ) (1983 ) (1961 ) Received date: Revised date: First author: LI Qing (1983 ), male, doctorial candidate. kevinlee2007@126.com Correspondent author: XIAO Hanning (1961 ), male, Ph.D., professor. hnxiao@hnu.edu.cn

2 SiC TaC TaC SiC SiC TaC SiC TaC TEOS ( 1:2:2:0.01) A TaCl 5 B B A C [ 1% 1% ( ) 5] 3 h A B C 60 12h 3 d SiO 2 Ta 2 O 5 A B C 3:2: TaCl % 1.2 SiO 2 Ta 2 O ST1 ST2 ST3 ST4 1.3 SiC TaC Ar /min 1 h D/max 2550PC X (Cu K α ) JSM-6700F Oxford Instmments SiO 2 Ta 2 O 5 SiO 2 Ta 2 O 5 TaCl 5 [16] TaCl 5 + 5EtOH Ta(OEt) 5 + 5HCl (1) [17] 2Ta(OEt) 5 + 5H 2 O Ta 2 O EtOH (2) TEOS [18] Si(OEt) 4 + 2H 2 O SiO 2 + 4EtOH (3) SiO 2 Ta 2 O 5 TaCl 5 HCl TEOS TEOS EtOH TaCl ( 1) ( 2) A EDS C O Si Ta 4 1 Fig. 1 Digital photo of compound gel Tanabe [19] SiO 2 Ta 2 O 5 SiO 2 Si O Ta 2 O 5 Ta O Tanabe SiO 2 Ta 2 O 5

3 40 5 SiC TaC 741 ( 3 ) B EDS Si O Ta C 4 Si O Ta C B C O A H 2 O CO x 2 SEM EDS Fig. 2 SEM photograph and EDS spectrum of compound gel [20] Ta O [5/6 2/2] = Ta O = Ta O 1 Tanabe 1 1 Ta O Ta O SiO 2 Ta 2 O 5 5 [21] Ta O SiO 2 Ta 2 O [22] 3 SEM EDS Fig. 3 SEM photograph and EDS spectrum of hybrid precursor 2.3 SiC TaC SiO 2 Ta 2 O 5 SiC TaC

4 [23 24] SiO 2 + 3C SiC+2CO (4) Ta 2 O 5 + 7C 2TaC + 5CO (5) 4 XRD 60 SiO SiO 2 TaC SiC ( 5) SiC TaC SiO 2 SiO SiO 2 SiO 2 SiC SiC SiC TaC TaC TaC SiC TaC SiO SiC TaC SiC TaC 2.4 SiC TaC SiC TaC 2θ SiC TaC SiC TaC Fig. 5 Back scattering image and the corresponding EDS spectrum of SiC TaC nanopowders synthesized at XRD Fig. 4 XRD patterns of compound gel and synthesized nanopowder SiC TaC SiC TaC [12] SiC TaC SiC TaC 5 EDS SiC TaC SiC TaC SiC TaC ( 6)

5 40 5 SiC TaC SiC ( 6a) Ta Si Ta Si [25] 0.02 SiC TaC ( 6b) 0.05 SiC TaC SiC 0.1 SiC 100 nm TaC SiC SiC [26] TaC 3 1) TaCl 5 TEOS C 6 H 12 O 6 H 2 O 450 C SiO 2 Ta 2 O SiC TaC 2) Si O Ta C 3) SiC TaC 0.02 SiC TaC SiC SiC TaC TaC TaC SiC TaC Fig. 6 Morphology of SiC TaC nanopowders with different TaC contents synthesized at Note: Mole ratio of Ta to Si in samples ST1 to ST4 were 0.01, 0.02, 0.05, 0.1, respectively. [1] CHOYKE W J, MATSUNAMI H. Silicon Carbide, Recent Major Advances [M]. Berlin: Kyoto and Newyork: Springer, 2003: [2] POL V G, POL S V, GEDANKEN A. Thermal decomposition of commercial cilicone oil to produce high yield high surface area SiC nanorods [J]. J Phys Chem B, 2006, 110(23): [3],,. SiC [J]., 2002, 17(2): CHU Zengyong, FENG Chunxiang, SONG Yongcai, et al. J Inorg Mater (in Chinese), 2002, 17(2):

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