- Full text:
- PDF (eReader) / PDF (Download) (1369 kB)
We have performed 75 As nuclear magnetic resonance (NMR) and nuclear quadrupole resonance (NQR) measurements on single-crystalline Ba 1- x K x Fe 2 As 2 for x = 0.27–1. 75 As nuclear quadruple resonance frequency (ν Q ) increases linearly with increasing x . The Knight shift K in the normal state shows Pauli paramagnetic behavior with a weak temperature T dependence. K increases gradually with increasing x . By contrast, the nuclear spin–lattice relaxation rate 1/ T 1 in the normal state has a strong T dependence, which indicates the existence of large antiferomagnetic (AF) spin fluctuations for all x 's. The T dependence of 1/ T 1 shows a gaplike behavior below approximately 100 K for 0.6 < x < 0.9. This behaviors is well explained by the change in the band structure with the expansion of hole Fermi surfaces and the shrinkage and disappearance of electron Fermi surfaces at the Brillouin zone (BZ) with increasing x . The anisotropy of 1/ T 1 , represented by the ratio of 1/ T 1 a b to 1/ T 1 c , is always larger than 1 for all x 's, which indicates that stripe-type AF fluctuations are dominant in this system. The K in the superconducting (SC) state decreases, which corresponds to the appearance of spin-singlet superconductivity. The T dependence of 1/ T 1 in the SC state indicates a multiple-SC-gap feature. A simple two-gap model analysis shows that the larger superconducting gap gradually decreases with increasing x from 0.27 to 1 and a smaller gap decreases rapidly and nearly vanishes for x > 0.6 where electron pockets in BZ disappear.
References
- 1 Y.Kamihara, T.Watanabe, M.Hirano, and H.Hosono:J. Am. Chem. Soc. 130 (2008) 3296. Crossref, Google Scholar
- 2 Z. A.Ren, J.Yang, W.Lu, W.Yi, G. C.Che, X. L.Dong, L. L.Sun, and Z. X.Zhao: Mater. Res. Innovations 12 (2008) 105. Crossref, Google Scholar
- 3 K.Miyazawa, K.Kihou, P. M.Shirage, C.-H.Lee, H.Kito, H.Eisaki, and A.Iyo:J. Phys. Soc. Jpn. 78 (2009) 034712. Link, Google Scholar
- 4 M.Rotter, M.Pangerl, M.Tegel, and D.Johrendt: Angew. Chem., Int. Ed. 47 (2008) 7949. Crossref, Google Scholar
- 5 A. S.Sefat, R.Jin, M. A.McGuire, B. C.Sales, D. J.Singh, and D.Mandrus:Phys. Rev. Lett. 101 (2008) 117004. Crossref, Google Scholar
- 6 S.Jiang, H.Xing, G.Xuan, C.Wang, Z.Ren, C.Feng, J.Dai, Z.Xu, and G.Cao:J. Phys.: Condens. Matter 21 (2009) 382203. Crossref, Google Scholar
- 7 S.Kasahara, T.Shibauchi, K.Hashimoto, K.Ikada, S.Tonegawa, R.Okazaki, H.Shishido, H.Ikeda, H.Takeya, K.Hirata, T.Terashima, and Y.Matsuda:Phys. Rev. B 81 (2010) 184519. Crossref, Google Scholar
- 8 P. L.Alireza, Y. T.Chris Ko, J.Gillett, C. M.Petrone, J. M.Cole, G. G.Lonzarich, and S. E.Sebastian:J. Phys.: Condens. Matter 21 (2009) 012208. Crossref, Google Scholar
- 9 T.Yamazaki, N.Takeshita, R.Kobayashi, H.Fukazawa, Y.Kohori, and K.Kihou:Phys. Rev. B 81 (2010) 224511. Crossref, Google Scholar
- 10 J.-Ph.Reid, M. A.Tanatar, X. G.Luo, H.Shakeripour, N.Doiron-Leyraud, N.Ni, S. L.Bud'ko, P. C.Canfield, R.Prozorov, and L.Taillefer:Phys. Rev. B 82 (2010) 64501. Crossref, Google Scholar
- 11 M.Yamashita, Y.Senshu, T.Shibauchi, S.Kasahara, K.Hashimoto, D.Watanabe, H.Ikeda, T.Terashima, I.Vekhter, A. B.Vorontsov, and Y.Matsuda:Phys. Rev. B 84 (2001) 060507. Crossref, Google Scholar
- 12 K.Suzuki, H.Usui, and K.Kuroki:J. Phys. Soc. Jpn. 80 (2011) 013710. Link, Google Scholar
- 13 K.Hashimoto, T.Shibauchi, S.Kasahara, K.Ikada, S.Tonegawa, T.Kato, R.Okazaki, C. J.van der Beek, M.Konczykowski, H.Takeya, K.Hirata, T.Terashima, and Y.Matsuda:Phys. Rev. Lett. 102 (2009) 207001. Crossref, Google Scholar
- 14 R.Khasanov, D. V.Evtushinsky, A.Amato, H.-H.Klauss, H.Luetkens, Ch.Niedermayer, B.Büchner, G. L.Sun, C. T.Lin, J. T.Park, D. S.Inosov, and V.Hinkov:Phys. Rev. Lett. 102 (2009) 187005. Crossref, Google Scholar
- 15 H.Ding, P.Richard, K.Nakayama, K.Sugawara, T.Arakane, Y.Sekiba, A.Takayama, S.Souma, T.Sato, T.Takahashi, Z.Wang, X.Dai, Z.Fang, G. F.Chen, J. L.Luo, and N. L.Wang:Europhys. Lett. 83 (2008) 47001. Crossref, Google Scholar
- 16 I. I.Mazin, D. J.Singh, M. D.Johannes, and M. H.Du:Phys. Rev. Lett. 101 (2008) 057003. Crossref, Google Scholar
- 17 H.Ikeda:J. Phys. Soc. Jpn. 77 (2008) 123707. Link, Google Scholar
- 18 Y.Nagai, N.Hayashi, N.Nakai, H.Nakamura, M.Okumura, and M.Machida: N. J. Phys. 10 (2008) 103026. Crossref, Google Scholar
- 19 K.Suzuki, H.Usui, and K.Kuroki:Phys. Rev. B 84 (2011) 144514. Crossref, Google Scholar
- 20 M.Yashima, H.Nishimura, H.Mukuda, Y.Kitaoka, K.Miyazawa, P. M.Shirage, K.Kiho, H.Kito, H.Eisaki, and A.Iyo:J. Phys. Soc. Jpn. 78 (2009) 103702. Link, Google Scholar
- 21 K.Matano, Z. A.Ren, X. L.Dong, L. L.Sun, Z. X.Zhao, and G.-q.Zheng:Europhys. Lett. 83 (2008) 57001. Crossref, Google Scholar
- 22 S.Onari and H.Kontani:Phys. Rev. Lett. 103 (2009) 177001. Crossref, Google Scholar
- 23 K.Sano and Y.Ono:J. Phys. Soc. Jpn. 78 (2009) 124706. Link, Google Scholar
- 24 Y.Yanagi, Y.Yamakawa, and Y.Ono:Phys. Rev. B 81 (2010) 054518. Crossref, Google Scholar
- 25 S.Onari and H.Kontani:Phys. Rev. B 84 (2011) 144518. Crossref, Google Scholar
- 26 H.Kontani, T.Saito, and S.Onari:Phys. Rev. B 84 (2011) 024528. Crossref, Google Scholar
- 27 H.Fukazawa, Y.Yamada, K.Kondo, T.Saito, Y.Kohori, K.Kuga, Y.Matsumoto, S.Nakatsuji, H.Kito, P. M.Shirage, K.Kihou, N.Takeshita, C. H.Lee, A.Iyo, and H.Eisaki:J. Phys. Soc. Jpn. 78 (2009) 083712. Link, Google Scholar
- 28 K.Hashimoto, A.Serafin, S.Tonegawa, R.Katsumata, R.Okazaki, T.Saito, H.Fukazawa, Y.Kohori, K.Kihou, C. H.Lee, A.Iyo, H.Eisaki, H.Ikeda, Y.Matsuda, A.Carrington, and T.Shibauchi:Phys. Rev. B 82 (2010) 014526. Crossref, Google Scholar
- 29 J. K.Dong, S. Y.Zhou, T. Y.Guan, H.Zhang, Y. F.Dai, X.Qiu, X. F.Wang, Y.He, X. H.Chen, and S. Y.Li:Phys. Rev. Lett. 104 (2010) 087005. Crossref, Google Scholar
- 30 H.Kawano-Furukawa, C. J.Bowell, J. S.White, R. W.Heslop, A. S.Cameron, E. M.Forgan, K.Kihou, C. H.Lee, A.Iyo, H.Eisaki, T.Saito, H.Fukazawa, Y.Kohori, R.Cubitt, C. D.Dewhurst, J. L.Gavilano, and M.Zolliker:Phys. Rev. B 84 (2011) 024507. Crossref, Google Scholar
- 31 K.Ohishi, Y.Ishii, H.Fukazawa, T.Saito, I.Watanabe, Y.Kohori, T.Suzuki, K.Kihou, C. H.Lee, K.Miyazawa, H.Kito, A.Iyo, and H.Eisaki: arXiv:1112.6078. Google Scholar
- 32 K.Okazaki: private communication. Google Scholar
- 33 Y.Aoki: private communication. Google Scholar
- 34 R.Thomale, C.Platt, W.Hanke, J.Hu, and B. A.Bernevig:Phys. Rev. Lett. 107 (2011) 117001. Crossref, Google Scholar
- 35 C. H.Lee, K.Kihou, H.Kawano-Furukawa, T.Saito, A.Iyo, H.Eisaki, H.Fukazawa, Y.Kohori, K.Suzuki, H.Usui, K.Kuroki, and K.Yamada:Phys. Rev. Lett. 106 (2011) 067003. Crossref, Google Scholar
- 36 T.Sato, K.Nakayama, Y.Sekiba, P.Richard, Y.-M.Xu, S.Souma, T.Takahashi, G. F.Chen, J. L.Luo, N. L.Wang, and H.Ding:Phys. Rev. Lett. 103 (2009) 047002. Crossref, Google Scholar
- 37 T.Terashima, M.Kimata, N.Kurita, H.Satsukawa, A.Harada, K.Hazama, M.Imai, A.Sato, K.Kihou, C. H.Lee, H.Kito, H.Eisaki, A.Iyo, T.Saito, H.Fukazawa, Y.Kohori, H.Harima, and S.Uji:J. Phys. Soc. Jpn. 79 (2010) 053702. Link, Google Scholar
- 38 K.Nakayama, T.Sato, P.Richard, Y.-M.Xu, T.Kawahara, K.Umezawa, T.Qian, M.Neupane, G. F.Chen, H.Ding, and T.Takahashi:Phys. Rev. B 83 (2011) 020501. Crossref, Google Scholar
- 39 K.Kihou, T.Saito, S.Ishida, M.Nakajima, Y.Tomioka, H.Fukazawa, Y.Kohori, T.Ito, S.-I.Uchida, A.Iyo, C. H.Lee, and H.Eisaki:J. Phys. Soc. Jpn. 79 (2010) 124713. Link, Google Scholar
- 40 H.Fukazawa, T.Yamazaki, K.Kendo, Y.Kohori, N.Takeshita, P. M.Shirage, K.Kihou, K.Miyazawa, H.Kito, H.Eisaki, and A.Iyo:J. Phys. Soc. Jpn. 78 (2009) 033704. Link, Google Scholar
- 41 T. J.Bastow:J. Phys.: Condens. Matter 11 (1999) 569. Crossref, Google Scholar
- 42 P.Blaha, K.Schwarz, G. K. H.Madsen, D.Kvasnicka, and J.Luitz: inWIEN2K, An Augmented Plane Wave Plus Local OrbitalsProgram for Calculating Crystal Properties, ed. by K.Schwarz (Tech. Univ. Wien, Vienna, 2001). Google Scholar
- 43 D. J.Singh:Phys. Rev. B 79 (2009) 174520. Crossref, Google Scholar
- 44 K.Kitagawa, N.Katayama, K.Ohgushi, M.Yoshida, and M.Takigawa:J. Phys. Soc. Jpn. 77 (2008) 114709. Link, Google Scholar
- 45 H.Fukazawa, T.Saito, Y.Yamada, K.Kondo, M.Hirano, Y.Kohori, K.Kuga, A.Sakai, Y.Matsumoto, S.Nakatsuji, K.Kihou, A.Iyo, C. H.Lee, and H.Eisaki:J. Phys. Soc. Jpn. 80 (2011) SA118. Link, Google Scholar
- 46 E.Wiesenmayer, H.Luetkens, G.Pascua, R.Khasanov, A.Amato, H.Potts, B.Banusch, H.-H.Klauss, and D.Johrendt:Phys. Rev. Lett. 107 (2011) 237001. Crossref, Google Scholar
- 47 Y.Nakai, T.Iye, S.Kitagawa, K.Ishida, H.Ikeda, S.Kasahara, H.Shishido, T.Shibauchi, Y.Matsuda, and T.Terashima:Phys. Rev. Lett. 105 (2010) 107003. Crossref, Google Scholar
- 48 F.Ning, K.Ahilan, T.Imai, A. S.Sefat, R.Jin, M. A.Mcguire, B. C.Sales, and D.Mandrus:J. Phys. Soc. Jpn. 77 (2008) 103705. Link, Google Scholar
- 49 K.Matano, Z.Li, G. L.Sun, D. L.Sun, C. T.Lin, M.Ichioka, G.-q. Zheng: Europhys. Lett. 87 (2009) 27012. Crossref, Google Scholar
- 50 W. W.Simmons, W. J.O'Sullivan, and W. A.Robinson:Phys. Rev. 127 (1962) 1168. Crossref, Google Scholar
- 51 H.Ikeda, R.Arita, and J.Kunes:Phys. Rev. B 82 (2010) 024508. Crossref, Google Scholar
- 52 Recently, the new compound KxFe2Se2 and related compounds, which can be considered to be electron-doped system, have been found [J. G. Guo, S. F. Jin, G. Wang, S. C. Wang, K. X. Zhu, T. T. Zhou, M. He, and X. L. Chen:Phys. Rev. B82(2010) 180520]. However, in this paper, we concentrate on the discussion about the hole- and electron-doped system, which is related to BaFe2As2 as the parent compound. Google Scholar
- 53 Y.Sekiba, T.Sato, K.Nakayama, K.Terashima, P.Richard, J. H.Bowen, H.Ding, Y.-M.Xu, L. J.Li, G. H.Cao, Z.-A.Xu, and T.Takahashi:New. J. Phys. 11 (2009) 025020. Crossref, Google Scholar
- 54 W.Malaeb, T.Yoshida, A.Fujimori, M.Kubota, K.Ono, K.Kihou, P. M.Shirage, H.Kito, A.Iyo, H.Eisaki, and Y.Kakajima:J. Phys. Soc. Jpn. 78 (2009) 123706. Link, Google Scholar
- 55 T.Yoshida, I.Nishi, A.Fujimori, M.Yi, R. G.Moore, D.-H.Lu, Z.-X.Shen, K.Kihou, P. M.Shirage, H.Kito, C. H.Lee, A.Iyo, H.Eisaki, and H.Harima:J. Phys. Chem. Solids 72 (2011) 465. Crossref, Google Scholar
- 56 W.Malaeb: private communication. Google Scholar
- 57 J.-P.Castellan, S.Rosenkranz, E. A.Goremychkin, D. Y.Chung, I. S.Todorov, M. G.Kanatzidis, I.Eremin, J.Knolle, A. V.Chubukov, S.Maiti, M. R.Norman, F.Weber, H.Claus, T.Guidi, R. I.Bewley, and R.Osborn:Phys. Rev. Lett. 107 (2011) 177003. Crossref, Google Scholar
- 58 T.Moriya:J. Magn. Magn. Mater. 100 (1991) 261. Crossref, Google Scholar
- 59 S.Kitagawa, Y.Nakai, T.Iye, K.Ishida, Y.Kamihara, M.Hirano, and H.Hosono:Phys. Rev. B 81 (2010) 212502. Crossref, Google Scholar
- 60 Here, we express the wave vector with the notation in the BZ for the orthorhombic Fmmm structure although the actual wave vector should be expressed with that for the tetragonal I4/mmm structure. This is because it is complicated to separate the off-diagonal component with the wave vector of (π,π) in the present form into those with the wave vector in the form with BZ for the tetragonal I4/mmm structure. Google Scholar
- 61 Z.Li, D. L.Sun, C. T.Lin, Y. H.Su, J. P.Hu, and G.-q. Zheng: Phys. Rev. B 83 (2011) 140506. Crossref, Google Scholar
- 62 S. W.Zhang, L.Ma, Y. D.Hou, J. S.Zhang, T. L.Xia, G. F.Chen, J. P.Hu, G. M.Luke, and W.Yu:Phys. Rev. B 81 (2010) 012503. Crossref, Google Scholar