Mo-La材料固-液喷雾掺杂过程掺杂物反应机制分析

ANALYSIS OF THE REACTION MECHANISM OF DOPANTS DURING THE SOLID- LIQUID SPRAY DOPING PROCESS OF MO-LA MATERIAL

通过对硝酸镧晶体进行差热分析,获得TG、DTG和DSC曲线,进而确定3个温度拐点。在这3个温度下,对硝酸镧进行空气气氛的热分解试验和固-液喷雾掺杂工艺模拟试验,并对其反应产物进行XRD分析。按照Mo O2-50La(NO3)3的化学配比,进行Mo-La材料的固-液喷雾掺杂试验,对掺杂Mo O2进行XRD分析。这3试验结果证明,在传统喷雾掺杂过程中,硝酸镧无论呈晶体形式还是水溶液形式,均只通过脱水反应转变为La(NO3)3.4H2O,而不会发生热分解产生La2O3、NO和/或NO2,掺杂过程产生的氮氧化合物烟气污染是由于硝酸分解所得。并分析了硝酸的来源。

In the three break temperatures, which were obtained by TG/DTG/DSC curves of lanthanum nitrate crystal, the air thermal decomposition and solid - liquid spray doping simulation experiments of lanthanum nitrate crystal were carried out, and their products were analyzed by XRD. Meanwhile, according to the chemical formula of MoO2-50La（ NO3 ） 3, the spray doping processing of Mo-La material is undergone, and doped MoO2 was analyzed by XRD. The results demonstrated that during the traditional solid - liquid spray doping processing, lanthanum nitrate, in the form of crystal or aqueous solution, would not be decomposed to La2O3 and NO or NO2, but be converted into La（ NO3 ） 3- 4H2O by the dehydration reaction, and that the oxynitride gas pollution produced by the processing was due to decomposition of HNO3. And the source of HNO3 is theoretically presented.