实验技术与管理2025，Vol.42Issue(4)：20-25,6.DOI:10.16791/j.cnki.sjg.2025.04.003
基于第一性原理计算的双层二维材料ReTe2滑移铁电性质研究实验设计
Experimental design for studying the slip ferroelectric properties of double-layer two-dimensional material ReTe2 based on first-principles calculations
摘要
Abstract
[Objective]With the rapid development of society,integrated circuits have become the foundation of the information age,occupying an important position in communications,aerospace,automotive electronics,and other fields.As one of the core development aspects of integrated circuits,the pursuit of high performance and miniaturization of memory is continuously advancing.Ferroelectric random access memory,with its nonvolatile data storage characteristics and advantages,such as unlimited read/write cycles,high-speed read/write,and low power consumption,is highly favored by researchers.To pursue simplicity and miniaturization of electronic components in integrated circuits,the development of low-dimensional ferroelectric materials can meet the requirements of compactness and high-density storage based on miniature size.Two-dimensional materials with nanoscale dimensions have become potential options for achieving ferroelectric miniaturization.This research introduces a two-dimensional ferroelectric material based on transition-metal chalcogenides,i.e.,ReTe2,and systematically introduces the calculation-based design process of this material through the calculation of its structural phonon spectrum,molecular dynamics,slip path,potential barrier,charge density difference,ferroelectric polarization intensity,and electrostatic potential.[Methods]This work uses the Materials Studio modeling tool(Visualizer)to convert the ReTe2 bulk material structure model downloaded from the crystal database website into a double-layer two-dimensional ferroelectric model.First-principles methods are used to calculate the energy of relative slip between the upper and lower layers of double-layer two-dimensional ReTe2,thereby obtaining the two ferroelectric state structures A and A' with the lowest energy and the intermediate state B for the transition between these two ferroelectric states.The phonon spectrum software Phonopy based on VASP(Vienna Ab-initio Simulation Package)and the first-principles dynamics method(AIMD,Ab-initio Molecular Dynamics)of VASP are used to calculate the structural and thermodynamic stability of ReTe2.The ferroelectric polarization intensity of ReTe2 is obtained using the Berry phase method.By setting the calculation parameters of VASP,the plane-averaged electrostatic potential and charge density difference of ReTe2 can be obtained to analyze its electronic distribution characteristics and the origin of ferroelectricity.[Results]The following results were obtained through the first-principles calculations:(1)The structure of double-layer two-dimensional ReTe2 is determined based on corresponding movement and inversion of the ReTe2 bulk material,thereby meeting the symmetry requirements of two-dimensional slip ferroelectric materials:the symmetry requirement for two-dimensional sliding ferroelectric materials is that a single layer must either have inversion symmetry but lack a horizontal mirror plane(A/B stacking),or have a horizontal mirror plane but lack inversion symmetry(A/A stacking),with opposite sliding ferroelectric states connected by a horizontal mirror plane.The results of phonon spectrum analysis and molecular dynamics calculations showed that this two-dimensional structure,which relies on van der Waals forces between the two layers,has structural and thermodynamic stability.(2)The ferroelectric polarization intensity of ReTe2 calculated using the Berry phase method in VASP is 0.915 pC/m,and the energy barrier during the slip process is 8.08 meV.These results indicate that ReTe2 has a large ferroelectric slip and a small slip barrier,making it an ideal two-dimensional ferroelectric slip material.(3)The calculation and analysis of the plane-averaged electrostatic potential and differential charge density of ReTe2 showed that the source of ferroelectricity in ReTe2 can be attributed to the relative displacement of the double layers,causing a difference in net charge transfer between the top and bottom layers,thereby generating two-dimensional vertical polarization.The polarization direction reverses with different movement directions,exhibiting typical ferroelectric characteristics.[Conclusion]The analysis of the structural characteristics,plane-averaged electrostatic potential,and differential charge density showed that the double-layer two-dimensional ReTe2 is a typical two-dimensional ferroelectric slip material.This experimental method can be used to confirm determine whether new materials can be used as two-dimensional ferroelectric slip materials.In addition,by mastering the experimental analysis process,students'scientific interest and overall scientific literacy in exploring microscopic mechanisms and processes can be cultivated.关键词
第一性原理计算/滑移铁电/二维材料/铁电极化强度Key words
first-principles calculations/slip ferroelectricity/two-dimensional materials/ferroelectric polarization intensity分类
数理科学引用本文复制引用
郭建新,崔皓桢,杨保柱,王富,闫小兵..基于第一性原理计算的双层二维材料ReTe2滑移铁电性质研究实验设计[J].实验技术与管理,2025,42(4):20-25,6.基金项目
国家自然科学基金区域联合项目(U23A20365) （U23A20365）
河北省自然科学基金项目(F2022201002) （F2022201002）
河北省教育厅教改项目(2023cxcy001) （2023cxcy001）
