碳化硅的总硅量测定,分解样品是其关键之一。采用在银坩埚中用NaOH和Na_2O_2(2:1)的混合熔剂,在700℃下熔融20分钟分解样品。由于SiC中的总硅量达70%左右,所以用500μg/100ml的标谁SiO_2溶液作为参比溶液,以硅钼蓝示差分光光度法测定SiC中的总硅量。本方法的最大吸收波长λ=800nm。该波长处的表观摩尔吸光系数ε=2.51×10~4。 Determination of the total silicon carbide silicon, decomposition of the sample is one of the key. The sample was decomposed by melting in a silver crucible with a mixed flux of NaOH and Na 2 O 2 (2: 1) at 700 ° C for 20 minutes. Since the total amount of silicon in SiC reaches about 70%, the total amount of silicon in SiC is determined by silicon molybdenum blue differential spectrophotometry using a standard solution of 500 g / 100 ml of SiO 2 as a reference solution. The maximum absorption wavelength of this method is λ = 800 nm. The apparent molar absorptivity ε = 2.51 × 10 ~ 4 at this wavelength.