研究了加速器质谱测量用NH₄Hf₂F₉ 的制备方法, 用XRD, SEM, XPS 和TG-DTA 表征其结构和组成. 结果表明:NH₄Hf₂F₉ 样品在573 K 热处理1 h 后物相并未变化, 而在773, 973, 1173, 1373 K 热处理1 h 后物相则都转变为HfO₂.TG-DTA 的分析表明从573 K 开始NH₄Hf₂F₉ 样品逐渐开始分解, 至1073 K 时失重约78%. 样品微观形貌为不规则的固体颗粒, 颗粒的粒径分布较大, 范围在5～20 μm 之间. 粉末样品主要含有Hf, N 和F 元素, 其中Hf 主要以(+4)价存在.

The method of multiphase synthesis of NH₄Hf₂F₉ for accelerator mass spectrometry (AMS) measurement was researched. The structure and composition of NH₄Hf₂F₉ powder were characterized by XRD, SEM, XPS and TG-DTA. When the NH₄Hf₂F₉ powder was heated at 573 K for 1 h, the powder phase was still NH₄Hf₂F₉. After being heated at 773, 973, 1173 and 1373 K for 1 h, respectively, they all transformed to HfO₂. When the temperature was above 573 K, NH₄Hf₂F₉ powder began to decompose. When the temperature reached 1073 K, the weight loss of NH₄Hf₂F₉ powder was about 78%. The powder shape was irregular, and powder size was between 5 and 20 μm in the SEM images. The XPS results show that there were Hf, N and Hf in NH₄Hf₂F₉ powder, and Hf mainly existed in quadrivalent state (+4).