【摘 要】
：
The lanthana-doped mullite fibers were prepared via a sol-gel method from the aluminum isopropoxide-aluminum nitrate-tetraethyl orthosilicate system.The structu
【机 构】
：
State Key Laboratory of New Ceramics & Fine Process,The SecondArtillery NCO Academy of PLA
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The lanthana-doped mullite fibers were prepared via a sol-gel method from the aluminum isopropoxide-aluminum nitrate-tetraethyl orthosilicate system.The structure evolution and thermal stability of the mullite fibers were investigated by means of X-ray diffraction (XRD),Fourier transform infrared (FT-IR) spectroscopy,differential scanning calorimetry (DSC),scanning electron microscopy (SEM) and transmission electron microscopy (TEM).The results showed that the fibers obtained after calcination at 1000℃ was in the form of A12O3-rich mullite,which tended to transform to stoichiometric mullite with the lanthana content increasing.The lattice parameter a exhibited a decline trend with the lanthana content increasing,while b showed an upward tendency.Correspondingly,the redshift of Si-O-Si bond from 1255 to 1245 cm-1 was observed.The grain growth was inhibited for the doped fibers,among which the 5％ La2O3-doped sample presented a minimum crystallite size (17.2 nm) after calcination at 1000 ℃ for 1 h.
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