摘要
利用高能炸药爆轰驱动冲击波、狭缝扫描闪光隙高速照相技术和阻抗匹配解原理,在10—100GPa压力范围内,测量了BaCO_3和TiO_2 粉末混合物的冲击缘热数据。同时,利用轴对称柱面和平面爆轰装置,进行了该混合物样品的冲击后回收实验和回收样品的X射线衍射分析,考察 BaTiO_3的冲击合成。 测量出的冲击绝热数据,以冲击波压力和比容平面上的结果为例,在约 30和45 GPa两个压力值时,比容发生明显跃变。冲击绝热数据与回收样品X射线衍射分析结果相结合,判断出,这两个跃变分别对应于 TiO_2 从锐钛矿相转变到高压β-TiO_2 相,BaCO_3与TiO_2开始急剧化学反应合成出BaTiO_3 并放出CO_2。此外,在压力为10GPa左右作回收实验,其回收样品的X射线衍射分析表明TiO_2由锐钛矿相完全转变为金红石相。
Hugoniot data for powder mixture of BaCO3 and TiO2 have been measured in the range 10 to lOOGPa according to impedance match principle using chemical explosive driven shock wave and flash gap slit sweeping photography of high speed rotating mirror camera. Recovery experiments with axial synmmetic and planar configurations and X-ray diffraction of recovered sample in order to examine shock synthesis of BaTiO3 have conduc -ted as well.Measured Hugoniot curves show obvious discontinuities at about 30 and 45GPa. Hugoniot data combined with X-ray diffraction analyses show that those discontinuities correspond to the phase transition of TiO2 in the mentioned mixture from the anatase to theβ-TiO2 phase and synthesised BaTiO, reaction between BaCO3 and TiO2. respectively. Moreover. X-ray diffraction analyses of recovered samples using ammonium nitrate charge indicate that the very complete transition of TiO2 from the anatase phase to the rutile phase occured.
出处
《高压物理学报》
CAS
CSCD
北大核心
1989年第1期67-77,共11页
Chinese Journal of High Pressure Physics
