Lin Chih-Ming, Liu Hsin-Tzu, Zhong Shi-Yao, Hsu Chia-Hung, Chiu Yi-Te, Tai Ming-Fong, Juang Jenh-Yih, Chuang Yu-Chun, Liao Yen-Fa
Department of Applied Science, National Hsinchu University of Education, Hsinchu 30014, Taiwan.
Department of Chemical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan.
Materials (Basel). 2016 Jul 12;9(7):561. doi: 10.3390/ma9070561.
Nanosized aluminum-doped zinc oxide ZnAlO (AZO) powders (AZO-NPs) with = 0.01, 0.03, 0.06, 0.09 and 0.11 were synthesized by chemical precipitation method. The thermogravimetric analysis (TGA) indicated that the precursors were converted to oxides from hydroxides near 250 °C, which were then heated to 500 °C for subsequent thermal processes to obtain preliminary powders. The obtained preliminary powders were then calcined at 500 °C for three hours. The structure and morphology of the products were measured and characterized by angle-dispersive X-ray diffraction (ADXRD) and scanning electron microscopy (SEM). ADXRD results showed that AZO-NPs with Al content less than 11% exhibited würtzite zinc oxide structure and there was no other impurity phase in the AZO-NPs, suggesting substitutional doping of Al on Zn sites. The ZnAlO powders (A₃ZO-NPs) with grain size of about 21.4 nm were used for high-pressure measurements. The in situ ADXRD measurements revealed that, for loading run, the pressure-induced würtzite (B4)-to-rocksalt (B1) structural phase transition began at 9.0(1) GPa. Compared to the predicted phase-transition pressure of 12.7 GPa for pristine ZnO nanocrystals of similar grain size (21.4 nm), the transition pressure for the present A₃ZO-NPs exhibited a reduction of ~3.7 GPa. The significant reduction in phase-transition pressure is attributed to the effects of highly selective site occupation, namely Zn and Al, were mainly found in tetrahedral and octahedral sites, respectively.
采用化学沉淀法合成了铝掺杂量（x）分别为0.01、0.03、0.06、0.09和0.11的纳米氧化锌铝（ZnAlO，AZO）粉末（AZO-NPs）。热重分析（TGA）表明，前驱体在250℃左右由氢氧化物转化为氧化物，然后加热至500℃进行后续热处理以获得初步粉末。将所得初步粉末在500℃煅烧3小时。通过角分辨X射线衍射（ADXRD）和扫描电子显微镜（SEM）对产物的结构和形貌进行了测量和表征。ADXRD结果表明，铝含量小于11%的AZO-NPs呈现纤锌矿氧化锌结构，且AZO-NPs中无其他杂质相，表明铝在锌位点上进行了替代掺杂。将粒径约为21.4 nm的ZnAlO粉末（A₃ZO-NPs）用于高压测量。原位ADXRD测量结果表明，在加载过程中，压力诱导的纤锌矿（B4）到岩盐（B1）的结构相变在9.0(1) GPa开始。与类似粒径（~21.4 nm）的原始ZnO纳米晶体预测的约12.7 GPa的相变压力相比，当前A₃ZO-NPs的相变压力降低了约3.7 GPa。相变压力的显著降低归因于高度选择性的位点占据效应，即锌和铝主要分别位于四面体和八面体位点。
