压力诱导CsCu_(2)I_(3)不可逆非晶化和金属化

Pressure-Induced Irreversible Amorphization and Metallization of CsCu_(2)I_(3)

近年来,压力作用下卤化物钙钛矿的结构和性质引起了科学家们的极大兴趣。然而,对于高压下钙钛矿非晶相的潜在性质和应用仍缺乏深入系统的研究。利用金刚石对顶砧,结合原位高压同步辐射X射线衍射、原位高压拉曼光谱、高压变温电学测量技术,对准一维卤化物钙钛矿CsCu_(2)I_(3)在高压下的非晶化行为进行了系统的研究。结果表明:CsCu_(2)I_(3)在35.9 GPa以上开始出现可逆的压致非晶化,形成低密度的非晶态Ⅰ相;在更高压力下,发生由低密度到高密度的非晶转变,形成非晶态Ⅱ相,并可以截获至常压条件。进一步的电学实验表明,136.0 GPa时,CsCu_(2)I_(3)发生了由绝缘体向金属相的转变,对高压下金属相的非晶态进行卸压电阻测试,发现其金属特性至少可稳定至90.0 GPa。这些结果为进一步探索非晶钙钛矿的潜在性质和应用提供了重要的科学依据。

Exploring the structures and properties of halide perovskite under pressure have triggered great interest among scientists in recent years.However,there is still little understanding on the potential properties and applications of their amorphous phase under high pressure.In this paper,we utilized diamond anvil cell,combined with in situ high pressure synchrotron radiation X-ray diffraction,Raman spectroscopy and electrical resistance measurement to investigated the amorphization of quasi-one-dimensional halide perovskite CsCu_(2)I_(3)under high pressure.It was observed that CsCu_(2)I_(3)started to transform to a reversible lowdensity amorphous phaseⅠabove 35.9 GPa.An irreversible high density amorphous phaseⅡwas realized at higher pressure,which can be maintained to ambient pressure.With the application of pressure up to 136.0 GPa,the initially insulating CsCu_(2)I_(3)transform to a metallic phase.In addition,the metallic amorphous phaseⅡcan be preserved to at least 90.0 GPa.These results provide an important scientific basis for further exploring the potential properties and applications of amorphous perovskite.