Title <研究ノート>鉄系超伝導体1111系と122系における核磁気共鳴(NMR)

Author(s) 中井, 祐介

Citation 低温物質科学研究センター誌 : LTMセンター誌 (2010),16: 10-17

Issue Date 2010-06-01

URL https://doi.org/10.14989/153257

Right

Type Departmental Bulletin Paper

Textversion publisher

Kyoto University

1111 122 (NMR)

NMR study on the 1111 and 122 iron pnictide superconductors

, JST-TRIP

Yusuke Nakai

Graduate School of Science, Kyoto University, JST-TRIP

Spin dynamics and superconducting properties in the 1111 and 122 iron pnictides high-temperature

superconductors have been investigated via nuclear magnetic resonance (NMR) technique. Although

unconventional superconducting gaps in these materials have been inferred from the temperature dependence of

the nuclear spin-lattice relaxation rate T1-1, their superconducting gap structures likely differ each other. We also

discuss correlations between spin fluctuations and superconductivity in these materials.

2008 LaFeAs(O1-xFx) [1],

.

, , 55 K Tc

[2].

, Tc 4 K LaFePO[3] 2006

, . ,

1111 122

[4-7]. , 1111 122 (NMR) ,

, ,

[8].

. , , ,

, , , ,

, , ,

.

1 , 4 . 1111

(RFeAsO, R = ), 122 (AFe2As2, A = Ca, Sr, Ba), 111 (BFeAs, B = Na, Li), 11 (FeCn, Cn =

S, Se, Te) . 1 Fe- (P, As )

(Se, Te ) , .

c , ,

10

, 2(a) .

2(b) , [9] 3d ,

.

, .

, .

,

, ( ) . 2(a)

, M .

, 3 ,

.

tetragonal orthorhombic ( 3 T0),

[10] 11 [11] . 122 1111

, 122 ,

2 LaFeAsO (a) (b) [9] M

M (b) d

d

(a) (b) (c) (d)

1 (a)1111 RFeAsO R (b)122 AFe2As2 A = Ca, Sr, Ba (c)111 BFeAs, B = Na,

Li (d)11 FeCn, Cn = S, Se, Te P, As, Sb

S, Se, Te

11

, 1111 10 K ,

. 3(a) , 1111 ,

, 1111 ,

. LaFeAs(O,F) , ,

[12]. , 122

, [13].

,

. ,

[16, 17]. ,

,

s

. , , s

Tc [18].

LaFe(As1-xOx) NMR

NMR . NMR

, T1-1

. , LaFeAs(O1-xFx) (T1T)-1 4 [5, 6].

LaFeAsO , (T1T)-1 ,

, 140 K . ,

, (x 0.07)

. , Tc x = 0.11 ,

(a)

FeAs(O1-x

Fx) (Ba

1-xK

x)Fe

2As

2

(b)

P concentration

AF

N

N

0

N

0

N

3 (a)1111 RFeAs(O,F) (R = La, Ce, Sm) [14] (b)122 BaFe2(As,P)2 [15] AF

SC T0(TN) 1111

La

122

Tc

12

(T1T = ) , (T1T)-1

.

x = 0.04 0.11

, (T1T)-1

, Tc ( 4 )

. ,

,

.

, 5

, s Tc

T1-1 Tc

T1-1

, T1-1 T 3

. LaFeAs(O,F)

[19-22] .

T1-1 ,

d

.

, d

, T1-1

T 3 T1-1 T

[23].

1111

,

, d

. ,

PrFeAsO1-

,

[24].

.

BaFe2(As1-xPx)2 NMR

, 122 As P BaFe2(As1-xPx)2 NMR

[7]. . LaFeAs(O1-xFx)

Pseudogap

SC

AFM

4 LaFeAs(O1-xFx) (T1T)-1

LaFeAs(O1-xFx)

Tc TN x =

0.07 T* (T1T)-1

(T1T)-1= a + b exp(- /T)

x 11%

“Pseudogap”

5 LaFeAs(O0.89F0.11), BaFe2(As0.67P0.33)2, (Ba0.6K0.4)Fe2As2

Tc T1-1

Tc Tc

Tc

13

,

. , dHvA

,

[15, 25]. 6 Ba122

(Ba,K)Fe2As2[26, 27],

Ba(Fe,Co)2As2[28], P

BaFe2(As,P)2[7]

Tc (T1T)-1

.

Tc ,

.

,

Tc

[Tc ((Ba0.6K0.4)Fe2As2) = 38 K > Tc

(BaFe2(As0.67P0.33)2) = 30 K > Tc

(Ba(Fe0.92Co0.08)2As2) = 22 K].

122 ,

, 5 BaFe2(As0.67P0.33)2

, Tc , T1-1

[7]. , ,

. , BaFe2(As0.67P0.33)2

, [31], [32], .

, Ba122 (Ba0.6K0.4)Fe2As2 ,

BaFe2(As0.67P0.33)2 . 5

, (Ba0.6K0.4)Fe2As2 , T1-1

T 5 [30], BaFe2(As0.67P0.33)2

. (Ba,K)Fe2As2 (ARPES)[33]

[34] , 2 , (Ba0.6K0.4)Fe2As2

NMR . BaFe2(As0.67P0.33)2 (Tc = 30 K) (Ba0.6K0.4)Fe2As2 (Tc =

38 K) , Tc,

, ,

.

1111 122

LaFeAs(O,F) Ba122 , (1)

, (2)Tc

(LaFeAs(O,F): T1-1 T 3, BaFe2(As,P)2: T, (Ba,K)Fe2As2: T 5) .

, Tc T1-1 T 3 , 11 FeSe [35, 36, 37].

6 122 1111 As

(T1T)-1 [7] BaFe2As2(TN = 135 K)

[29] (Ba0.6K0.4)Fe2As2 (Tc = 38 K) [26, 30]

BaFe2(As0.67P0.33) (Tc = 30 K) [7]

Ba(Fe0.92Co0.08)2As2(Tc = 22 K) [28] LaFeAs(O0.89F0.11) (Tc

= 25 K) [5] LaFeAsO0.6 (Tc = 28 K) [20]

14

, ,

. ,

LaFeAs(O,F) T1-1 T 3 , s [38-42].

, Tc ,

s . , LaFeAs(O,F) Tc T1-1 T 5

T 6 [43, 44] ,

[45, 46], 1111 ,

. , Ba122 , s

[18]. ,

(10 K ) , Tc

BaFe2(As,P)2 (Tc = 30 K) (Ba,K)Fe2As2 (Tc = 38 K) ,

. ,

[47, 48].

,

.

1111 122

, LaFeAs(O,F)

Ba122 . Ba122 Tc , (T1T)-1

,

. 11 [49, 36,

37].

. 122 11 , LaFeAs(O,F)

, . , NMR

mK , NMR

. , ,

(1) LaFeAs(O1-xFx)( 4 x = 0.07 0.11 ) LaFeAsO

, (2)Tc ( 4 x = 0.14 )

[50]. , (meV )

, NMR

. , LaFeAs(O,F)

[51, 52],

. 122

11 LaFeAs(O1-xFx) , 1111

.

, 1111 122

, 122

.

15

,

. , 5

, , , ,

. ,

Tc ,

.

, ,

. JST-TRIP, Global

COE

, . NMR

,

. .

[1] Y. Kamihara et al., J. Am. Chem. Soc. , 3296 (2008).

[2] K. Shimizu et al., Nature , 316 (2001).

[3] Y. Kamihara et al., J. Am. Chem. Soc. , 10012 (2006).

[4] Y. Nakai et al., Phys. Rev. Lett. , 077006 (2008).

[5] Y. Nakai et al., J. Phys. Soc. Jpn. , 073701 (2008).

[6] Y. Nakai et al., New J. Phys. , 045004 (2009).

[7] Y. Nakai et al., Phys. Rev. B , 020503(R) (2010).

[8] , vol.64 No. 11 (2009). Ishida et al., J. Phys. Soc. Jpn. , 062001 (2009).

[9] D. J. Singh and M.-H. Du, Phys. Rev. Lett. , 237003 (2008).

[10] C. de la Cruz et al., Nature , 899 (2008).

[11] S. Li et al., Phys. Rev. B , 054503 (2009).

[12] H. Luetkens et al., Nature Mater. , 305 (2009).

[13] J.-H. Chu et al., Phys. Rev. B , 014506 (2009).

[14] Y. J. Uemura, Nature Materials , 253 (2009).

[15] S. Kasahara et al., arXiv:0905.4427 (2009).

[16] I. I. Mazin et al., Phys. Rev. Lett. , 057003 (2008).

[17] K. Kuroki et al., Phys. Rev. Lett. , 087004 (2008).

[18] K. Kuroki et al., Phys. Rev. B , 224511 (2009).

[19] K. Ahilan et al., Phys. Rev. B , 100501(R) (2008).

[20] H. Mukuda et al., J. Phys. Soc. Jpn. , 093704 (2008).

[21] H.-J. Grafe et al., Phys. Rev. Lett. , 047003 (2008).

[22] T. Nakano et al., arXiv:0909.0318 (2009).

[23] K. Ishida et al., J. Phys. Soc. Jpn. , 2803 (1993).

[24] K. Hashimoto et al., Phys. Rev. Lett. , 017002 (2009).

16

[25] H. Shishido et al., Phys. Rev. Lett. , 057008 (2010).

[26] H. Fukazawa et al., J. Phys. Soc. Jpn. , 033704 (2009).

[27] H. Mukuda et al., Physica C , 559 (2009).

[28] F. Ning et al., J. Phys. Soc. Jpn. , 013711 (2009).

[29] K. Kitagawa et al., J. Phys. Soc. Jpn. , 114709 (2008).

[30] M. Yashima et al., J. Phys. Soc. Jpn. , 103702 (2009).

[31] K. Hashimoto et al., arXiv:0907.4399 (2009).

[32] J. S. Kim et al., arXiv:1002.3355 (2010).

[33] H. Ding et al., arXiv:0812.0534 (2008).

[34] K. Hashimoto et al., Phys. Rev. Lett. , 207001 (2009).

[35] H. Kotegawa et al., J. Phys. Soc. Jpn. , 113703 (2008).

[36] Y. Shimizu et al., J. Phys. Soc. Jpn. , 123709 (2009).

[37] C. Michioka et al., arXiv:0911.3729 (2009).

[38] D. Parker et al., Phys. Rev. B , 134524 (2008).

[39] A. V. Chubukov et al., Phys. Rev. B , 134512 (2008).

[40] M. M. Parish et al., Phys. Rev. B , 144514 (2008).

[41] Y. Bang, H.-Y. Choi, and H. Won, Phys. Rev. B , 054529 (2009).

[42] Y. Nagai et al. New J. Phys. , 103026 (2008).

[43] Y. Kobayashi et al., J. Phys. Soc. Jpn. , 073704 (2009).

[44] F. Hammerath et al., arXiv:0912.3682 (2009).

[45] K. Matano et al., Europhys. Lett. , 57001 (2008).

[46] S. Kawasaki et al., Phys. Rev. B , 220506(R) (2008).

[47] A. V. Chubukov et al., Phys. Rev. B , 140515(R) (2009).

[48] T. A. Maier et al., Phys. Rev. B , 224510 (2009).

[49] T. Imai et al., Phys. Rev. Lett. , 177005 (2009).

[50] S. Wakimoto et al., arXiv:0906.2453 (2009).

[51] H. Ikeda, J. Phys. Soc. Jpn. , 123707 (2008).

[52] H. Ikeda et al., arXiv:1002.4471 (2010).

Yusuke Nakai

(PD)

Tel: 075-753-3752

nakai@scphys.kyoto-u.ac.jp

2006 3

2009 3

2008 4

17