钙钛矿稀土镍酸盐SmNiO3薄膜的研究进展

Research on Progress in Perovskite Nickelate SmNiO3 Film

强关联性量子材料SmNiO3属于钙钛矿镍氧化物,在海水中具有与鲨鱼壶腹相似的弱电感知能力,是新型水下电场传感器敏感元件,可监测海洋中的舰船、无人潜航器,为反潜提供新的探测手段,引起了广泛的关注。对SmNiO3薄膜的制备方法及优缺点对比进行了详细的论述,由于SmNiO3具有正的吉布斯自由能(ΔG),常温常压下SmNiO3中的Ni^3+处于亚稳态,制备过程中易于发生Ni^3+→Ni^2+,为保持电中性,氧空位会作为其补偿形式,而氧缺陷会导致SmNiO3薄膜晶格参数变大,从而摧毁金属-绝缘体转变,因此制备SmNiO3需要高温高氧压苛刻的实验条件来降低ΔG。重点介绍了SmNiO3薄膜材料的相变类型、机制及影响相变温度的主要因素,大多数研究认为,SmNiO3的MI相变是基于Mott的电子-电子强关联引起的,实际上无序和电子-电子相互作用应该同时存在,不应该单独考虑某一种相变类型,MI相变实质是低温下载流子之间的库伦作用,应将热激活机制、Mott变程跳跃传导和Efros-Shklovskii变程跳跃传导机制在一定温度范围内综合考虑;在电场、温度、光及压力等外界环境作用下,SmNiO3薄膜会发生明显的金属-绝缘体相变,相变温度TMI也随之改变。最后展望了SmNiO3薄膜在电场传感器元件、数据存储、智能窗帘以及调制开关等方面的发展前景。

Perovskite structure rare-earth nickelate SmNiO3 film has recently aroused wide attention in academia for its good weak electric sense,which is analogous to that of the ampullae of shark.It can be postulated that SmNiO3 could be used in oceanic environments for monitoring electrical signals from maritime vessels and sea creatures.In this paper,the preparation method,advantages and disadvantages of SmNiO3 film are discussed in detail.SmNiO3,this strongly correlated quantum materials has positive Gibbs Free Energy(ΔG).Thus,preparation of SmNiO3 needs hush experimental conditions such as high pressure and temperature. Since Ni^3+ is semi-stable at room temperature and atmospheric pressure, the process of Ni^3+→Ni^2+ iseasy to occur. In order to maintain electrical neutrality, oxygen vacancies would appear in the form of compensation. That is thereason most SmNiO3 film prepared by researchers has oxygen deficiency. While oxygen deficiency would lead to larger latticeparameters, and destroy metal-insulator phase transition. Therefore, the preparation of SmNiO3 requires higher temperature andoxygen pressure. The metal-insulator phase change type, mechanism and main factors affecting the TMI of SmNiO3 thin filmmaterials are mainly introduced: most studies consider that the MI phase transition of SmNiO3 film is caused by the strongelectron-electron correlation of Mott type, which is actually disordered and electron-electron interactions should exist at thesame time. MI phase change should not be considered separately, which is essentially the coulomb interaction in charge carriersat lower temperature. The thermal activated conduction, Mott variable range hopping conduction and Efros-Shklovskii variablerange hopping conduction should be considered in a certain temperature range. Under external conditions such as electric field,temperature, light and pressure, SmNiO3 film would undergo a significant metal-insulator phase transition. And finally, aprospect SmNiO3 film in underwater electric field sensors, data storage, modulation swithches, etc.