[1]李 健,茅伟华,黄桂芹.铁基超导材料FeTe0.5Se0.5的第一性原理研究[J].南京师大学报(自然科学版),2013,36(01):43-47.
 Li Jian,Mao Weihua,Huang Guiqin.First-Principles Study of Iron-Based Superconducting Material FeTe0.5Se0.5[J].Journal of Nanjing Normal University(Natural Science Edition),2013,36(01):43-47.
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铁基超导材料FeTe0.5Se0.5的第一性原理研究()
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《南京师大学报(自然科学版)》[ISSN:1001-4616/CN:32-1239/N]

卷:
第36卷
期数:
2013年01期
页码:
43-47
栏目:
物理学
出版日期:
2013-03-31

文章信息/Info

Title:
First-Principles Study of Iron-Based Superconducting Material FeTe0.5Se0.5
作者:
李 健1茅伟华2黄桂芹1
(1.南京师范大学物理科学与技术学院,江苏 南京 210023) (2.江苏省吴江市青云实验中学,江苏 吴江 215235)
Author(s):
Li Jian1Mao Weihua2Huang Guiqin1
(1.School of Physics and Technology,Nanjing Normal University,Nanjing 210023,China) (2.Qingyun Experimental Middle School,Wujiang 215235,China)
关键词:
铁基超导晶格动力学电声子相互作用第一性原理
Keywords:
iron-based superconductorlattice dynamicselectron-phonon interactionfirst-principles
分类号:
O511+.4
摘要:
采用第一性原理计算了FeTe0.5Se0.5在两种不同结构模型下的电子结构、晶格动力学以及电声子相互作用.结果表明:用两种结构模型计算得到的电子结构大致相同,费米面附近的态密度主要来自Fe d电子的贡献.对两种模型我们根据不可约表示分析了Γ点的光学模频率,并给出了声子谱及声子态密度.用模型1和模型2计算得到的电声子耦合常数λ分别为0.20和0.22,都非常弱,无法解释实验上较高的超导转变温度.因此,超导材料FeTe0.5Se0.5和其他的铁基超导材料一样,都不属于常规的电声子耦合超导材料.
Abstract:
The electronic structure,lattice dynamics and electron-phonon interaction of FeTe0.5Se0.5 in two different structural models are investigated by using the first-principles.The results show that the electronic structures of the two structural models are similar to each other,and the electronic density of states near the Fermi level comes mainly from Fe d electrons.For both two models,we analyze the optical modes at the Γ point based on irreducible representation,and give the phonon spectra and the phonon density of the states.The electron-phonon coupling coefficients λ calculated by model 1 and model 2 are 0.20 and 0.22,respectively,which are both too small to explain the high superconducting transition temperature discovered in experiment.Therefore,we think that superconducting material FeTe0.5Se0.5 doesn’t belong to the conventional electron-phonon coupling mechanism,which is similar to the other Fe-based superconducting materials.

参考文献/References:

[1] Kamihara Y,Watanabe T,Hirano M,et al.Iron-based layered superconductor La[O1-xFx]FeAs(x=0.05-0.12)with Tc=26K[J].J Am Chem Soc,2008,130(11):3 296-3 297.
[2]Sefat A S,Jin R Y,McGuire M A,et al.Superconductivity at 22 K in Co-doped BaFe2As2 crystal[J].Phys Rev Lett,2008,101:117004-1-117004-4.
[3]Tapp J H,Tang Z J,Lü B,et al.LiFeAs:an intrinsic FeAs-based superconductor with Tc=18 K[J].Phys Rev B,2008,78:060505-1-060505-4.
[4]Boeri L,Dolgov O V,Golubo V A A.Is LaFeAsO1-xFx an electron-phonon superconductor[J].Phys Rev Lett,2008,101:026403-1-026403-4.
[5]Yildirim T.Strong coupling of the Fe-spin state and the As-As hybridization in iron-pnictide superconductors from first-principle calculations[J].Phys Rev Lett,2009,102:037003-1-037003-4.
[6]Mc Guire M A,Christianson A D,Sefat A S,et al.Phase transitions in LaFeAsO:structure,magnetic,elastic,and transport properties,heat capacity and Mossbauer spectra[J].Phys Rev B,2008,78:094517-1-094517-10.
[7]Liu R H,Wu T,Wu G,et al.A large iron isotope effect in SmFeAsO1-xFx and Ba1-xKxFe2As2[J].Nature,2009,459:64-67.
[8]Huang G Q,Xing Z W,Xing D Y.Spin-phonon coupling and effect of pressure in the superconductor LiFeAs:lattice dynamics from first-principles calculations[J].Phys Rev B,2010,82:014511-1-014511-7.
[9]Hsu F C,Luo J Y,Yeh K W,et al.Superconductivity in the PbO-type structure α-FeSe[J].Proc Natl Acad Sci USA,2008,105:14 262-14 264.
[10]Li Shiliang,Clarina de la Cruz,Huang Q,et al.First-order magnetic and structural phase transitions in Fe1+ySexTe1-x[J].Phys Rev B,2009,79:054503-1-054503-7.
[11]Shi H L,Huang Z B,Tse J S,et al.Magnetic behavior of Fe(Se,Te)systems:first-principles calculations[J].Journal of Applied Physics,2011,110:043917-1-043917-7.
[12]Subedi A,Zhang L,Singh D J,et al.Density functional study of FeS,FeSe,and FeTe:electronic structure,magnetism,phonons,and superconductivity[J].Phys Rev B,2008,78:134514-1-134504-6.
[13]Despina Louca,Horigane K,Llobet A,et al.Local atomic structure of superconducting FeSe1-xTex[J].Phys Rev B,2010,81:134524-1-134524-8.
[14]Perdew J P,Burke K,Ernzerhof M.Generalized gradient approximation made simple[J].Phys Rev Lett,1996,77:3 865-3 868.
[15]Methfessel M,Paxton A T.High-precision sampling for Brillouin-Zone integration in metals[J].Phys Rev B,1989,40:3 616-3 621.
[16]Xia T L,Hou D,Zhao S C,et al.Raman phonons of α-FeTe and Fe1.03Se0.3Te0.7 single crystals[J].Phys Rev B,2009,79:140510-1-140510-4.

备注/Memo

备注/Memo:
收稿日期:2012-06-15.
基金项目:国家自然科学基金(10947005).
通讯联系人:李健,硕士研究生,研究方向:凝聚态物理.E-mail:lijian2006400457@126.com
更新日期/Last Update: 2013-03-31