The Magnetic Suppression and Electronic Structure Evolution of K1-xFe2Se2 with Different K Vacancy Concentration
Tóm tắt
Magnetic and electronic structures of K1-xFe2Se2 (x = 0.0, 0.2, 0.4, 0.6, and 0.8) in collinear antiferromagnetic state were studied by first-principles calculations. With the increase of K vacancy concentration, the magnetic moment and Fe-Se bond length were decreased (from x = 0.0 to 0.6) first and then increased (from x = 0.6 to 0.8). When the K vacancy concentration was 0.6 (that is K0.4Fe2Se2), the magnetic moment was completely suppressed, and the Fe-Se bond was the smallest. In contrast, the hybridized band width (HBW) first increased and then decreased, reaching to the maximum for K0.4Fe2Se2. The electron Fermi surface shrank gradually and the hole Fermi surface grew. The calculated results explained why experimental K0.8Fe2Se2 showed superconductivity compared with KFe2Se2.
Tài liệu tham khảo
Kamihara, Y., Watanabe, T., Hirano, M., Hosono, H.: Iron-based layered superconductor La[O1-xFx]FeAs (x= 0.05–0.12) with Tc = 26 K. J. Am. Chem. Soc. 130, 3296–3297 (2008).
Chen, X.H., Wu, T., Wu, G., Liu, R.H., Chen, H., Fang, D.F.: Superconductivity at 43 K in SmFeAsO1-xFx. Nature 453, 07045 (2008)
Chen, G.F., Li, Z., Wu, D., Li, G., Hu, W.Z., Dong, J., Zheng, P., Luo, J.L., Wang, N.L.: Superconductivity at 41 K and its competition with spin-density-wave instability in layered CeO1-xFxFeAs. Phys. Rev. Lett. 100, 247002 (2008)
Ren, Z.A., Yang, J., Lu, W., Yi, W., Shen, X.L., Li, Z.C., Che, G.C., Dong, X.L., Sun, L.L., Zhou, F., Zhao, Z.X.: Superconductivity in the iron-based F-doped layered quaternary compound Nd[O1-xFx]FeAs. Europhys. Lett. 82, 57002 (2008)
Rotter, M., Tegel, M., Johrendt, D., Schellenberg, I., Hermes, W., Pottgen, R.: Spin-density-wave anomaly at 140 K in the ternary iron arsenide BaFe2As2. Phys. Rev. B 78, 020503 (2008)
Rotter, M., Tegel, M., Schellenberg, I., Schappacher, F.M., Poettgen, R., Deisenhofer, J., Guenther, A., Schrettle, F., Loidl, A., Johrendt, D.: Competition of magnetism and superconductivity in underdoped (Ba1-xKx)Fe2As2. New J. Phys. 11, 025014 (2009)
Rotter, M., Tegel, M., Johrendt, D.: Superconductivity at 38 K in the iron arsenide (Ba1-xKx)Fe2As2. Phys. Rev. Lett. 101, 107006 (2008)
Sasmal, K., Lv, B., Lorenz, B., Guloy, A.M., Chen, F., Xue, Y.Y., Chu, C.W.: Superconducting Fe-based compounds (A1-xSrx)Fe2As2 with A = K and Cs with transition temperatures up to 37 K. Phys. Rev. Lett. 101, 107007 (2008)
Ding, H., Richard, P., Nakayama, K., Sugawara, K., Arakane, T., Sekiba, Y., Takayama, A., Souma, S., Sato, T., Takahashi, T., Wang, Z., Dai, X., Fang, Z., Chen, G.F., Luo, J.L.: Observation of Fermi-surface–dependent nodeless superconducting gaps in Ba0.6K0.4Fe2As2. Europhys. Lett. 83, 47001 (2008).
Xu, G., Zhang, H.J., Dai, X., Fang, Z.: Electron-hole asymmetry and quantum critical point in hole-doped BaFe2As2. Europhys. Lett. 84, 67015 (2008)
Tapp, J.H., Tang, Z.J., Lv, B., Sasmal, K., Lorenz, B., Chu, P.C.W., Guloy, A.M.: LiFeAs: an intrinsic FeAs-based superconductor with Tc = 18K. Phys. Rev. B 78, 060505 (2008)
Hsu, F.C., Luo, J.Y., Yeh, K.W., Chen, T.K., Huang, T.W., Wu, P.M., Lee, Y.C., Huang, Y.L., Chu, Y.Y., Yan, D.C., Wu, M.K.: Superconductivity in the PbO-type structure α-FeSe. Proc. Natl. Acad. Sci. U. S. A. 105, 14262–14264 (2008)
Guo, J.G., Jin, S.F., Wang, G., Wang, S.C., Zhu, K., Zhou, T.T., He, M., Chen, X.L.: Superconductivity in the iron selenide KxFe2Se2 (0 ≤ x ≤ 1.0). Phys. Rev. B 82, 180520 (2010).
Cao, C., Dai, J.H.: Electronic structure of KFe2Se2 from first-principles calculations. Chin. Phys. Lett. 28, 057402 (2011)
Nekrasov, I.A., Sadovskii, M.V.: Electronic structure, topological phase transitions and superconductivity in (K, Cs)xFe2Se2. JETP Lett. 93, 166–169 (2011)
de la Cruz, C., Huang, Q., Lynn, J.W., Li, J., II, W.R., Zarestky, J.L., Mook, H.A., Chen, G.F., Luo, J.L., Wang, N.L.: Magnetic order close to superconductivity in the iron-based layered LaO1-xFxFeAs systems. Nature 453, 899–902 (2008).
Rotter, M., Hieke, C., Johrendt, D.: Different response of the crystal structure to isoelectronic doping in BaFe2(As1−xPx)2 and (Ba1−xSrx)Fe2As2. Phys. Rev. B 82, 014513 (2010)
Avci, S., Chmaissem, O., Chung, D.Y., Rosenkranz, S., Goremychkin, E.A., Castellan, J.P., Todorov, I.S., Schlueter, J.A., Claus, H., Daoud-Aladine, A., Khalyavin, D.D., Kanatzidis, M.G., Osbrn, R.: Phase diagram of Ba1-xKxFe2As2. Phys. Rev. B 85, 184507 (2012)
Cao, C., Dai, J.H.: Block spin ground state and three-dimensionality of (K,Tl)Fe1.6Se2. Phys. Rev. Lett. 107, 056401 (2011).
Cai, P., Ye, C., Ruan, W., Zhou, X.D., Wang, A.F., Zhang, M., Chen, X.H., Wang, Y.Y.: Imaging the coexistence of a superconducting phase and a charge-density modulation in the K0.73Fe1.67Se2 superconductor using a scanning tunneling microscope. Phys. Rev. B 85, 094512 (2012).
Qian, T, Wang, X.P., Jin, W.C., Zhang, P., Richard, P., Xu, G., Dai, X., Fang, Z., Guo, J.G., Chen, X.L., Ding, H.: Absence of a holelike Fermi surface for the iron-based K0.8Fe1.7Se2 superconductor revealed by angle-resolved photoemission spectroscopy. Phys. Rev. Lett. 106, 187001 (2011).
Yan, X.W., Gao, M., Lu, Z.Y., Xiang, T.: Electronic structures and magnetic order of ordered-Fe-vacancy ternary iron selenides TlFe1.5Se2 and AFe1.5Se2 (A = K, Rb, or Cs). Phys. Rev. Lett. 106, 087005 (2011).
Shein, I.R., Ivanovskii, A.L.: Electronic structure and Fermi surface of new K intercalated iron selenide superconductor KxFe2Se2. Phys. Lett. A 375, 1028–1031 (2011)
Mizuguchi, Y., Takeya, H., Kawasaki, Y., Ozak, T., Tsuda, S., Yamaguchi, T., Takano, Y.: Transport properties of the new Fe-based superconductor KxFe2Se2 (Tc = 33 K). Appl. Phys. Lett. 98, 042511 (2011)
Bellaiche, L., Vanderbilt, D.: Virtual crystal approximation revisited: application to dielectric and piezoelectric properties of perovskites. Phys. Rev. B 61, 7877–7882 (2000)
Payne, M.C., Teter, M.P., Allan, D.C., Arias, T.A., Joannopoulos, J.D.: Iterative minimization techniques for ab initio total-energy calculations: molecular dynamics and conjugate gradients. Rev. Mod. Phys. 64, 1045–1097 (1992)
Clark, S.J., Segall, M.D., Pickard, C.J., Hasnip, P.J., Probert, M.I., Refson, K., Payne, M.C.: First principles methods using CASTEP. Z. Kristallogr. 220, 567–570 (2005)
Perdew, J.P., Burke, K., Ernzerhof, M.: Generalized gradient approximation made simple. Phys. Rev. Lett. 77, 0031–9007 (1996)
Li, Y., Baggio-Saitovitch, E., Wang, Y.B., Cao, G.H., Chen, N., Zhao, Z.X., Wei, L.: Superconducting and microstructural properties of Fe-doped Tl-1223 cuprates. Physica C 315, 129–144 (1999)
Li, Y., Liu, Y., Duan, R.F., Xiong, X.T., Wang, B.Y., Cao, G.H., Wei, L., Zheng, D.N., Zhao, Z.X., Ross, J.H., Jr.: Positron annihilation study of the O-T phase transition for Eu1+xBa2−xCu3O7−δ superconductor. Physica C 402, 179–187 (2004)