Abstract
Various types of ground states in strongly correlated electron systems have been systematically investigated by means of NMR/NQR at low temperatures under high magnetic field and pressure. We focus on two well-known heavy-electron families, CeCu2X2 (X = Si and Ge) (Ce(122)) and UM2Al3 (M = Ni and Pd) (U(123)). The Cu NQR experiments on CeCu2X2 under high pressure indicate that the physical property of CeCu2Ge2 at high pressure, i.e. above the transition at 7.6 GPa from antiferromagnetic (AF) to superconductivity, are clearly related to tha CeCu2Si2 at ambient pressure. In addition to the H-T phase diagram established below 7 T, NMR and specific heat experiments on polycrystal CeCu2.05Si2 have revealed the presence of a new phase above 7 T. In a high-quality polycrystal of UPd2Al3 with a record high-Tc of 2 K at ambient pressure and the narrowest Al NQR line width, the nuclear-spin lattice relaxation rate, 27(1/T1) measured in zero field has been found to obey the T3 law down to 0.13 K, giving strong evidence that the energy gap vanishes along lines on the Fermi surface. Thus it seems that all heavy-electron superconductors exhibit lines of zero gap, regardless of their different magnetic properties.
| Original language | English |
|---|---|
| Pages (from-to) | 55-61 |
| Number of pages | 7 |
| Journal | Physica B: Condensed Matter |
| Volume | 206-207 |
| Issue number | C |
| DOIs | |
| Publication status | Published - Feb 1 1995 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Electrical and Electronic Engineering
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Materials Science(all)
Cite this
NMR study of strongly correlated electron systems. / Kitaoka, Y.; Tou, H.; Zheng, Guo-Qing; Ishida, K.; Asayama, K.; Kobayashi, Tatsuo; Kohda, A.; Takeshita, N.; Amaya, K.; Onuki, Y.; Geibel, G.; Schank, C.; Steglich, F.
In: Physica B: Condensed Matter, Vol. 206-207, No. C, 01.02.1995, p. 55-61.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - NMR study of strongly correlated electron systems
AU - Kitaoka, Y.
AU - Tou, H.
AU - Zheng, Guo-Qing
AU - Ishida, K.
AU - Asayama, K.
AU - Kobayashi, Tatsuo
AU - Kohda, A.
AU - Takeshita, N.
AU - Amaya, K.
AU - Onuki, Y.
AU - Geibel, G.
AU - Schank, C.
AU - Steglich, F.
PY - 1995/2/1
Y1 - 1995/2/1
N2 - Various types of ground states in strongly correlated electron systems have been systematically investigated by means of NMR/NQR at low temperatures under high magnetic field and pressure. We focus on two well-known heavy-electron families, CeCu2X2 (X = Si and Ge) (Ce(122)) and UM2Al3 (M = Ni and Pd) (U(123)). The Cu NQR experiments on CeCu2X2 under high pressure indicate that the physical property of CeCu2Ge2 at high pressure, i.e. above the transition at 7.6 GPa from antiferromagnetic (AF) to superconductivity, are clearly related to tha CeCu2Si2 at ambient pressure. In addition to the H-T phase diagram established below 7 T, NMR and specific heat experiments on polycrystal CeCu2.05Si2 have revealed the presence of a new phase above 7 T. In a high-quality polycrystal of UPd2Al3 with a record high-Tc of 2 K at ambient pressure and the narrowest Al NQR line width, the nuclear-spin lattice relaxation rate, 27(1/T1) measured in zero field has been found to obey the T3 law down to 0.13 K, giving strong evidence that the energy gap vanishes along lines on the Fermi surface. Thus it seems that all heavy-electron superconductors exhibit lines of zero gap, regardless of their different magnetic properties.
AB - Various types of ground states in strongly correlated electron systems have been systematically investigated by means of NMR/NQR at low temperatures under high magnetic field and pressure. We focus on two well-known heavy-electron families, CeCu2X2 (X = Si and Ge) (Ce(122)) and UM2Al3 (M = Ni and Pd) (U(123)). The Cu NQR experiments on CeCu2X2 under high pressure indicate that the physical property of CeCu2Ge2 at high pressure, i.e. above the transition at 7.6 GPa from antiferromagnetic (AF) to superconductivity, are clearly related to tha CeCu2Si2 at ambient pressure. In addition to the H-T phase diagram established below 7 T, NMR and specific heat experiments on polycrystal CeCu2.05Si2 have revealed the presence of a new phase above 7 T. In a high-quality polycrystal of UPd2Al3 with a record high-Tc of 2 K at ambient pressure and the narrowest Al NQR line width, the nuclear-spin lattice relaxation rate, 27(1/T1) measured in zero field has been found to obey the T3 law down to 0.13 K, giving strong evidence that the energy gap vanishes along lines on the Fermi surface. Thus it seems that all heavy-electron superconductors exhibit lines of zero gap, regardless of their different magnetic properties.
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UR - http://www.scopus.com/inward/citedby.url?scp=0029250186&partnerID=8YFLogxK
U2 - 10.1016/0921-4526(94)00365-3
DO - 10.1016/0921-4526(94)00365-3
M3 - Article
VL - 206-207
SP - 55
EP - 61
JO - Physica B: Condensed Matter
JF - Physica B: Condensed Matter
SN - 0921-4526
IS - C
ER -