亚稳相稀土镍基氧化物电子相变材料  

Rare-earth nickelates:The metastable oxides exhibiting multifold electronic phase transition functionalities

作　　者：陈吉堃[1] Jikun Chen(School of Materials Science and Engineering,University of Science and Technology Beijing,Beijing 100083,China)

机构地区：[1]北京科技大学材料科学与工程学院,北京100083

出　　处：《科学通报》2023年第1期100-111,共12页Chinese Science Bulletin

基　　金：国家重点研发计划(2021YFA0718900);国家自然科学基金(62074014)资助。

摘　　要：稀土镍基氧化物(ReNiO_(3))具有丰富的电子结构,在特征温度、特征压力、极化电场、化学或电化学氢化触发下可发生多重电子相变并引起材料物理性能的突变,该特性为设计制作新型强关联电子器件提供了宽广的探索空间.基于Ni^(3+)轨道价键歧化与反歧化所引起的金属绝缘体相转变特性,ReNiO_(3)特征触发温度(TMIT)可通过稀土元素组分实现在100~600 K宽广温区范围的连续调控,在突变式热敏电阻、红外伪装等方面具有潜在应用价值.此外,通过化学、电化学氢化触发ReNiO_(3)电子结构在基于Ni^(3+)的电子迅游态、Ni^(2+)的电子局域态、Ni^(1+)的超导相间的氢致电子相变自2014年以来被相继报道,并开启了对ReNiO_(3)应用于仿生电场传感器、面向人工智能的神经元逻辑器件、生物质传感等方面的全新探索.然而与传统氧化物材料所不同,除LaNiO_(3)(无金属绝缘体电子相变特性)以外的ReNiO_(3)均处于热力学亚稳相状态,其具有正向的吉布斯合成自由能而无法通过传统固相反应实现其材料生长;而ReNiO_(3)材料生长方面的技术难点在一定程度上制约了其基础探索与器件应用.当前有关ReNiO_(3)氢致电子相变、镍基超导等的前沿研究主要集中于轻、中稀土组分;而将上述基础探索拓展至重稀土元素组分依赖于其亚稳相材料制备技术的进一步发展.本文将结合上述ReNiO_(3)研究中的前沿动态,从ReNiO_(3)的温致电子相变与潜在应用、氢致电子相变与潜在应用、亚稳相材料生长中的关键技术这3个方面重点进行综述,并对ReNiO_(3)氢致电子相变机理、重稀土组分材料生长等未来研究中的关键性问题进行展望.Rare-earth nickelates(ReNiO_(3))belong to typical 3d-correlated transitional metal oxides with complex electronic structures.They exhibit multiple electronic phase transition properties that can be triggered by critical temperatures,critical pressures,electric charge polarizations,and electrical/electrochemical hydrogenations.This enriches the electronic functionalities and correlated electronic applications of ReNiO_(3),utilizing the abrupt variations in the physical properties triggered by electronic orbital transitions.The typical metal to insulator transition(MIT)of ReNiO_(3)originates from their charge disproportionation(or anti-disproportionation)associated with the Ni^(3+)orbital configurations.Compared with other material families exhibiting similar MIT functionality,the biggest advantage of ReNiO_(3)is the wide adjustability in its critical temperature(TMIT)within 100–600 K,as can be achieved simply by adjusting the rare-earth composition.This is,in particular,useful in potential applications,such as critical temperature resistor(CTR)or infrared camouflage,since the selection in TMITcatering for these applications can be further extended towards a low temperature range below room temperature.It well compensates the analogical functionalities of vanadium dioxide,as was usually used near or above room temperature.In addition,recently the chemical(or electrochemical)hydrogen triggered electronic phase transitions of ReNiO_(3),e.g.,from the Ni^(3+)based electron itinerant state to the Ni^(2+)based electron localized state,and further towards the Ni^(1+)based superconductive state,were discovered.It opens up a new paradigm to explore their correlated electronic applications of ReNiO_(3)in fields,such as ocean electric field detectors,neurosynaptic logical devices,and biosensors.In particular,it is worth noticing the recent discovery associated with the nickelate-based superconductivity in heavily hydrogenated Nd0.8Sr0.2NiO_(2)/Sr Ti O_(3)heterostructures enriches the material family of superconductive oxide

关 键 词：金属绝缘体电子相变 电子相变 稀土功能材料 钙钛矿氧化物 强关联半导体 

分 类 号：TB34[一般工业技术—材料科学与工程]