摘要基于密度泛函理论（DFT），运用广义梯度近似并考虑库仑作用修正（GGA+U）的方法，对层状铁氧化物CaFeO2和BaFeO2的几何结构，磁学特性，电学特性以及光学特性进行研究。磁学结构的计算表明：CaFeO2和BaFeO2的层间和层内的磁学相互作用各向异性。电学特性的研究揭示出：CaFeO2是一个带隙为2.7eV的绝缘体，而BaFeO2的则是带隙不足1eV的材料。通过态密度图的分析，可知CaFeO2和BaFeO2中Fe离子的电子的分布情况。光学特性的研究表明：这两种氧化物具有很好的各向异性。计算的结果将为CaFeO2和BaFeO2的应用提供理论指导。67112

毕业论文关键词   CaFeO2  BaFeO2  结构优化  电学特性  磁学特性  光学特性 GGA+U

毕业设计说明书（论文）外文摘要

Title   Investigation of electronic，magnetic and optical properties in infinite-layer iron oxide CaFeO2 and BaFeO2

Abstract

Based on density functional theory（DFT），we used the generalized gradient approximation plus on-site Coulomb repulsion method (GGA+U) to study the geometric, electronic, magnetic, and optical properties in infinite-layer iron oxide CaFeO2 and BaFeO2.The calculated results of the magnetic property shows there are magnetic anisotropies between interlayer and intralayer in both materials. The electronic structures show that the band gap in CaFeO2 is 2.7eV which is considered to be an insulator, while BaFeO2 is a material with band gap within 1eV. From the density of states (DOS), we could find the electrons' distribution of Fe ions. The linear optical response show obvious anisotropic in the two oxides. Our calculations give a comprehensive understanding of CaFeO2 and BaFeO2，also provide useful aspects of their potential application in various fields.

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Keywords     CaFeO2  BaFeO2   optimize structure   electronic property

                 Magnetic property   optical property     GGA+U

目   录

1  引言··1

2  理论背景··2

    2.1  计算方法··· 2

      2.1.1 第一性原理·2

       2.1.2 密度泛函理论·2

    2.2  软件简介··· 3

       2.2.1 Material Studio·4

       2.2.2 VASP4

3  计算及结果分析···5

    3.1  计算参数设置及计算结果处理··5

    3.2  结构优化 ··5

    3.3  磁学特性···7

    3.4  电学特性···9

      3.4.1态密度图 9

      3.4.2 能带结构··12

    3.5 电学特性13

     3.5.1  复介电常数···14

     3.5.2反射谱·16

     3.5.3吸收谱·17