Doping is critical for inducing ferroelectricity in hafnia films,yet the underlying mechanisms remain debated.Here,through first-principles studies,we elucidate the pivotal role played by the complex phase transition ...Doping is critical for inducing ferroelectricity in hafnia films,yet the underlying mechanisms remain debated.Here,through first-principles studies,we elucidate the pivotal role played by the complex phase transition mechanisms under carrier doping in understanding the origin of hafnia ferroelectricity.Specifically,electron doping orchestrates a metastable polar phase to stable antipolar phase transformation,driven by strong screening effects and weakened nonpolar covalent bonds,making n-type dopants rare.Conversely,weak screening effect and enhanced polar covalent bonding strengthen robust ferroelectricity,enabling significant ground-state phase transitions from the monoclinic to the polar orthorhombic phase and finally to the cubic phase under hole doping,a phenomenon prevalent in hafnia-based films doped with p-type dopants.Furthermore,this holeenhanced polar distortion also results in an inverse size effect in hafnia ferroelectric films,unlike perovskite ferroelectrics.Our findings offer new insights into the preparation of robust hafnia-based ferroelectric films through doping or interface engineering.展开更多
On December 10, our reporter learned from the Economic and Social Development & Reform Commission of Haixi Mongol and Tibetan Autonomous Prefecture that, all construction tasks of the Qinghai Salt Lake Group’s Ma...On December 10, our reporter learned from the Economic and Social Development & Reform Commission of Haixi Mongol and Tibetan Autonomous Prefecture that, all construction tasks of the Qinghai Salt Lake Group’s Magnesium Integration Project with a total investment展开更多
基金supported by financial support from the National Natural Science Foundation of China(Grant Nos.92164108 and U23A20322,51971188,51471139)the National Key Research and Development Program of China(2023YFF0719600)+4 种基金Hunan Provincial Natural Science Foundation(Grant Nos.2023JJ50009 and 2023JJ30599)the Guangdong Provincial Key Laboratory Program from the Department of Science and Technology of Guangdong Province(2021B1212040001)the Outstanding Youth Science Foundation of Hunan Province,China(Grant No.2021JJ20041)the Key Project of Scientific Research Fund of Hunan Provincial Education Department(Grant No.23A0150)the Chongqing Municipal Education Commission Science and Technology Research Program Youth Project(KJQN202101423).
文摘Doping is critical for inducing ferroelectricity in hafnia films,yet the underlying mechanisms remain debated.Here,through first-principles studies,we elucidate the pivotal role played by the complex phase transition mechanisms under carrier doping in understanding the origin of hafnia ferroelectricity.Specifically,electron doping orchestrates a metastable polar phase to stable antipolar phase transformation,driven by strong screening effects and weakened nonpolar covalent bonds,making n-type dopants rare.Conversely,weak screening effect and enhanced polar covalent bonding strengthen robust ferroelectricity,enabling significant ground-state phase transitions from the monoclinic to the polar orthorhombic phase and finally to the cubic phase under hole doping,a phenomenon prevalent in hafnia-based films doped with p-type dopants.Furthermore,this holeenhanced polar distortion also results in an inverse size effect in hafnia ferroelectric films,unlike perovskite ferroelectrics.Our findings offer new insights into the preparation of robust hafnia-based ferroelectric films through doping or interface engineering.
文摘On December 10, our reporter learned from the Economic and Social Development & Reform Commission of Haixi Mongol and Tibetan Autonomous Prefecture that, all construction tasks of the Qinghai Salt Lake Group’s Magnesium Integration Project with a total investment
