Electronic structure of vacancy-ordered iron-selenide K0.5Fe1.75Se2
Electronic structure of vacancy-ordered iron-selenide K0.5Fe1.75Se2
复制标题
空位有序硒化铁K0.5Fe1.75Se2的电子结构
DOI：
10.1103/physrevb.87.161105
复制
发表时间：
2013-04-11
影响因子：
3.7
通讯作者：
Zhang, Fuchun
中科院分区：
文献类型：
--
作者：
Cao, Chao;Zhang, Fuchun
用第一性原理密度泛函方法研究了空位有序的K0.5Fe1.75Se2铁硒化合物(278相)的电子结构。278相的基态为条带状反铁磁性，其裸电子磁化率在折叠布里渊区的(pi，pi)附近有一个大的峰。在费米能级附近，态密度主要由Fe-3D轨道控制，布里渊区同时出现类电子和类洞的费米面。未折叠的能带结构与空穴掺杂的122相显示出有限的相似性。当0.1e电子掺杂时，磁化率峰迅速被抑制和展宽，而类电子费米表面的二维性大大增强，从而产生了更好的嵌套行为。我们的研究应该与最近报道的超导相K0.5+xFe1.75+ySe2有关，其中x和y都很小。DOI：10.1103/PhysRevB.87.161105
The electronic structure of the vacancy-ordered K0.5Fe1.75Se2 iron-selenide compound (278 phase) is studied using the first-principles density functional method. The ground state of the 278 phase is stripelike antiferromagnetic, and its bare electron susceptibility shows a large peak around (pi, pi) in the folded Brillouin zone. Near the Fermi level, the density of states is dominated by the Fe-3d orbitals, and both electronlike and holelike Fermi surfaces appear in the Brillouin zone. An unfolded band structure shows limited similarities to a hole-doped 122 phase. With 0.1e electron doping, the susceptibility peak is quickly suppressed and broadened, while the two dimensionality of the electronlike Fermi surfaces is greatly enhanced, resulting in a better nesting behavior. Our study should be relevant to the recently reported superconducting phase K0.5+xFe1.75+ySe2 with both x and y being very tiny. DOI: 10.1103/PhysRevB.87.161105