Based on the transverse Ising model and using decoupling approximation to the Fermi-type Green'sfunction, we study the phase transition properties of the epitaxial ferroelectric film with one substrate.A generalre...Based on the transverse Ising model and using decoupling approximation to the Fermi-type Green'sfunction, we study the phase transition properties of the epitaxial ferroelectric film with one substrate.A generalrecursive equation of the ferroelectric thin film with two n-layer materials is obtained, which enables us to study thephase transition properties for any number layers for epitaxial ferroelectric thin film.With the help of this equation,we analyze the effect of the exchange interaction and the transverse field in the phase diagram, the influence to thepolarizations and Curie temperature numerically.The results show that epitaxial ferroelectric film are able to inducea strong increase or decrease of Curie temperature to different exchange interactions and transverse fields within theepitaxial film layers.The theoretical results are in reasonable accordance with experimental data of different ferroelectricthin film.展开更多
The dynamic phase transition properties for ferroelectric nanotube under a spin-1/2 transverse Ising model are studied under the effective field theory(EFT)with correlations.The temperature effects on the pseudo-spin ...The dynamic phase transition properties for ferroelectric nanotube under a spin-1/2 transverse Ising model are studied under the effective field theory(EFT)with correlations.The temperature effects on the pseudo-spin systems are unveiled in three-dimensional(3-D)and two-dimensional(2-D)phase diagrams.Moreover,the dynamic behaviors of exchange interactions on the 3-D and 2-D phase transitions under high temperature are exhibited.The results present that it is hard to obtain pure ferroelectric phase under high temperature;that is,the vibration of orderly pseudo-spins cannot be eliminated completely.展开更多
阳极尿素氧化反应(UOR)不仅可以取代析氧反应(OER)降低能耗,还可与析氢反应(HER)协同作用,同时产生氢燃料并净化富含尿素废水.然而,如何高效实现全电解尿素仍然面临挑战.本文首先将铑单原子催化剂(SAC)锚定到镍钒层状双氢氧化物(LDH)表...阳极尿素氧化反应(UOR)不仅可以取代析氧反应(OER)降低能耗,还可与析氢反应(HER)协同作用,同时产生氢燃料并净化富含尿素废水.然而,如何高效实现全电解尿素仍然面临挑战.本文首先将铑单原子催化剂(SAC)锚定到镍钒层状双氢氧化物(LDH)表面,以获得多功能电催化剂即Rh/NiV-LDH.该催化剂可以实现低能耗全电解尿素产氢目标.Rh/NiV-LDH在100 mV过电位下具有较高HER质量活性(0.262 A mg^(-1))和转化频率(TOF:2.125 s^(-1))此外,Rh/NiV-LDH表现出优异的UOR催化活性,仅需要1.33 V电压即可达到10 mA cm^(-2)的电流密度,表明UOR具备克服缓慢OER动力学缓慢的潜力.实验数据和理论计算证明,Rh/NiV-LDH出色的催化活性归因于NiV-LDH载体和单原子Rh位点的协同作用.将自支撑Rh/NiV-LDH分别作为尿素全电解池的阴极和阳极(1.0 mol L^(-1)KOH+0.33 mol L^(-1)尿素作为电解液),只需要1.47 V的低电压就可以提供100 mA cm^(-2)的电流密度且具有良好稳定性.这项工作从单原子精确调控的角度对全电解多功能SAC的设计具有重要指导意义.展开更多
基金Supported partly by SRF for ROCS,SEM under Grant No.20071108
文摘Based on the transverse Ising model and using decoupling approximation to the Fermi-type Green'sfunction, we study the phase transition properties of the epitaxial ferroelectric film with one substrate.A generalrecursive equation of the ferroelectric thin film with two n-layer materials is obtained, which enables us to study thephase transition properties for any number layers for epitaxial ferroelectric thin film.With the help of this equation,we analyze the effect of the exchange interaction and the transverse field in the phase diagram, the influence to thepolarizations and Curie temperature numerically.The results show that epitaxial ferroelectric film are able to inducea strong increase or decrease of Curie temperature to different exchange interactions and transverse fields within theepitaxial film layers.The theoretical results are in reasonable accordance with experimental data of different ferroelectricthin film.
基金Project supported by the National Key R&D Program of China(Grant No.2017YFE0120500)the National Natural Science Foundation of China(Grant No.51972129)+3 种基金the South Xinjiang Innovation and Development Program of Key Industries of Xinjiang Production and Construction Corps(Grant No.2020DB002)the Fundamental Research Funds for the Central Universities,China(Grant Nos.HUST 2018KFYYXJJ051 and 2019KFYXMBZ076)Shenzhen Fundamental Research Fund(Grant No.JCYJ20190813172609404)the Hubei“Chu-Tian Young Scholar”Program。
文摘The dynamic phase transition properties for ferroelectric nanotube under a spin-1/2 transverse Ising model are studied under the effective field theory(EFT)with correlations.The temperature effects on the pseudo-spin systems are unveiled in three-dimensional(3-D)and two-dimensional(2-D)phase diagrams.Moreover,the dynamic behaviors of exchange interactions on the 3-D and 2-D phase transitions under high temperature are exhibited.The results present that it is hard to obtain pure ferroelectric phase under high temperature;that is,the vibration of orderly pseudo-spins cannot be eliminated completely.
基金finically supported by the National Key R&D Program of China(2017YFE0120500)the National Natural Science Foundation of China(51972129,51702150,and 21725102)+2 种基金the Key Research and Development Program of Hubei(2020BAB079)Bintuan Science and Technology Program(2020DB002,and 2022DB009)the Science and Technology Innovation Committee Foundation of Shenzhen(JCYJ20210324141613032 and JCYJ20190809142019365)。
文摘阳极尿素氧化反应(UOR)不仅可以取代析氧反应(OER)降低能耗,还可与析氢反应(HER)协同作用,同时产生氢燃料并净化富含尿素废水.然而,如何高效实现全电解尿素仍然面临挑战.本文首先将铑单原子催化剂(SAC)锚定到镍钒层状双氢氧化物(LDH)表面,以获得多功能电催化剂即Rh/NiV-LDH.该催化剂可以实现低能耗全电解尿素产氢目标.Rh/NiV-LDH在100 mV过电位下具有较高HER质量活性(0.262 A mg^(-1))和转化频率(TOF:2.125 s^(-1))此外,Rh/NiV-LDH表现出优异的UOR催化活性,仅需要1.33 V电压即可达到10 mA cm^(-2)的电流密度,表明UOR具备克服缓慢OER动力学缓慢的潜力.实验数据和理论计算证明,Rh/NiV-LDH出色的催化活性归因于NiV-LDH载体和单原子Rh位点的协同作用.将自支撑Rh/NiV-LDH分别作为尿素全电解池的阴极和阳极(1.0 mol L^(-1)KOH+0.33 mol L^(-1)尿素作为电解液),只需要1.47 V的低电压就可以提供100 mA cm^(-2)的电流密度且具有良好稳定性.这项工作从单原子精确调控的角度对全电解多功能SAC的设计具有重要指导意义.
