NMR studies of layered nitride superconductors

被引：4

作者：

Tou, Hideki ^{[1
]}

Sera, Masafumi ^{[1
]}

Maniwa, Yutaka ^{[2
]}

Yamanaka, Shoji ^{[3
]}

机构：

[1] Hiroshima Univ, AdSM, Dept Quantum Matters, Hiroshima 7398530, Japan

[2] Tokyo Metropolitan Univ, Grad Sch Sci, Dept Phys, Tokyo 1200397, Japan

[3] Hiroshima Univ, Grad Sch Engn, Dept Appl Chem, Hiroshima 7398527, Japan

来源：

INTERNATIONAL JOURNAL OF MODERN PHYSICS B | 2007年 / 21卷 / 18-19期

关键词：

layered superconductor; NMR shift; NMR relaxation rate;

D O I：

10.1142/S0217979207044512

中图分类号：

O59 [应用物理学];

学科分类号：

摘要：

Layered nitride superconductor, Li-0.48(THF)(y)HfNCl with T-c=25.5 K, was investigated by means of nuclear magnetic resonance (NMR). Li-7-, Cl-35-NMR studies clarified that the partial electron density of states at Fermi level at Li and Cl sites are negligibly small. From the N-15 NMR Knight shift studies, the spin susceptibility decreases toward zero below T,, evidencing that the pairing symmetry is an even-parity spin-singlet. These results indicate that superconductivity is derived from the HfN layer. We also measured N-15-, Li-7-NMR spin-lattice relaxation rate in the temperature range of 4.2K - 100 K and observed the enhancement of the spin-lattice relaxation rate, 1/T-1, by field fluctuations generated by the vortex dynamics.

引用

页码：3340 / 3342

页数：3

共 11 条

[1] Electronic collective modes and superconductivity in layered conductors [J].

Bill, A ;

Morawitz, H ;

Kresin, VZ .

PHYSICAL REVIEW B, 2003, 68 (14)

[2] Electronic structures and instabilities of ZrNCl and HfNCl: implications for superconductivity in the doped compounds [J].

Felser, C ;

Seshadri, R .

JOURNAL OF MATERIALS CHEMISTRY, 1999, 9 (02) :459-464

[3] Electronic structure of superconducting layered zirconium and hafnium nitride [J].

Hase, I ;

Nishihara, Y .

PHYSICAL REVIEW B, 1999, 60 (03) :1573-1581

[4] NUCLEAR SPIN RELAXATION IN NORMAL AND SUPERCONDUCTING ALUMINUM [J].

HEBEL, LC ;

SLICHTER, CP .

PHYSICAL REVIEW, 1959, 113 (06) :1504-1519

[5] NMR relaxation rate in the superconducting state of the organic conductor kappa-(BEDT-TTF)(2)Cu[N(CN)(2)]Br [J].

Kanoda, K ;

Miyagawa, K ;

Kawamoto, A ;

Nakazawa, Y .

PHYSICAL REVIEW B, 1996, 54 (01) :76-79

[6] Superconducting characteristics in electron-doped layered hafnium nitride:: 15N isotope effect studies -: art. no. 100509 [J].

Tou, H ;

Maniwa, Y ;

Yamanaka, S .

PHYSICAL REVIEW B, 2003, 67 (10)

[7] Evidence for quasi-two-dimensional superconductivity in electron-doped Li0.48(THF)yHfNCl [J].

Tou, H ;

Maniwa, Y ;

Koiwasaki, T ;

Yamanaka, S .

PHYSICAL REVIEW B, 2001, 63 (02)

[8] Unconventional superconductivity in electron-doped layered Li0.48(THF)yHfNCl [J].

Tou, H ;

Maniwa, Y ;

Koiwasaki, T ;

Yamanaka, S .

PHYSICAL REVIEW LETTERS, 2001, 86 (25) :5775-5778

[9] μSR studies of intercalated HfNCl superconductor [J].

Uemura, YJ ;

Fudamoto, Y ;

Gat, IM ;

Larkin, MI ;

Luke, GM ;

Merrin, J ;

Kojima, KM ;

Itoh, K ;

Yamanaka, S ;

Heffner, RH ;

MacLaughlin, DE .

PHYSICA B, 2000, 289 :389-392

[10] Electron doping in the honeycomb bilayer superconductors (Zr, Hf)NCl [J].

Weht, R ;

Filippetti, A ;

Pickett, WE .

EUROPHYSICS LETTERS, 1999, 48 (03) :320-325

← 1 2 →