TY - JOUR
T1 - 63Cu NMR and NQR studies of high-Tc cuprates under pressure
AU - Zheng, Guo Qing
AU - Mito, Takeshi
AU - Kitaoka, Yoshio
AU - Asayama, Kunisuke
AU - Kodama, Yasuhiro
N1 - Funding Information:
The authors thank S. Endo for advice in constructing a high pressure device for NMR measurement. One of us (G-QZ) also thanks K. Ishida and S. Ohsugi for their interest and useful discussions. This work was partially supported by a grant-in-aid from the Ministry of Education, Science and Culture, Japan.
PY - 1995/3/1
Y1 - 1995/3/1
N2 - The spin-lattice relaxation rate 1/T1 and the Knight shift were measured for La1.85Sr0.15CuO4 and YBa2Cu4O8 under pressure to 1.4 GPa. The results together with the previously reported pressure dependence of the nuclear quadrupole frequency, νQ, give evidence that the local hole distribution changes under pressure. In La1.85Sr0.15CuO4, the hole density in the Cu 3d orbit decreases, accompanying a suppression of the antiferromagnetic spin fluctuation of the low-energy component. In YBa2Cu4O8, by contrast, the spin fluctuation changes little while the total hole number in the CuO2 plane increases. We argue that such changes in the hole distribution are responsible for the Tc increase in the respective compounds. We also found that the so-called "spin-gap" behavior in YBa2Cu4O8 becomes more pronounced under pressure.
AB - The spin-lattice relaxation rate 1/T1 and the Knight shift were measured for La1.85Sr0.15CuO4 and YBa2Cu4O8 under pressure to 1.4 GPa. The results together with the previously reported pressure dependence of the nuclear quadrupole frequency, νQ, give evidence that the local hole distribution changes under pressure. In La1.85Sr0.15CuO4, the hole density in the Cu 3d orbit decreases, accompanying a suppression of the antiferromagnetic spin fluctuation of the low-energy component. In YBa2Cu4O8, by contrast, the spin fluctuation changes little while the total hole number in the CuO2 plane increases. We argue that such changes in the hole distribution are responsible for the Tc increase in the respective compounds. We also found that the so-called "spin-gap" behavior in YBa2Cu4O8 becomes more pronounced under pressure.
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U2 - 10.1016/0921-4534(95)00029-1
DO - 10.1016/0921-4534(95)00029-1
M3 - Article
AN - SCOPUS:0029271497
SN - 0921-4534
VL - 243
SP - 337
EP - 341
JO - Physica C: Superconductivity and its applications
JF - Physica C: Superconductivity and its applications
IS - 3-4
ER -