TY - JOUR
T1 - O17 nuclear-magnetic-resonance spin-lattice relaxation and Knight-shift behavior in bismuthate, plumbate, and cuprate superconductors
AU - Reven, Linda
AU - Shore, Jay
AU - Yang, Shengtian
AU - Duncan, Todd
AU - Schwartz, Dwight
AU - Chung, Jim
AU - Oldfield, Eric
PY - 1991
Y1 - 1991
N2 - We have measured the O17 nuclear-magnetic-resonance spin-lattice relaxation times (T1) as a function of temperature for the CuO2 planar sites in Tl2Ba2CaCu2O8+x, YBa2Cu3O7-x, Bi2Sr2CaCu2O8+x, La1.85Sr0.15CuO4-x, La1.85Ca0.15CuO4-x, and Bi2Sr2CuO6+x, as well as for the oxygen sites in Ba0.6K0.4BiO3, BaBi0.25Pb0.75O3, BaSb0.25Pb0.75O3, and BaPbO3. The CuO2 planar sites in Tl2Ba2CaCu2O8+x, YBa2Cu3O7-x, and Bi2Sr2CaCu2O8+x exhibit close to ideal Korringa behavior in the normal state, characteristic of a good metal. In addition, the Knight shift of the CuO2 planes in these three materials is dominated by a spin contribution that is temperature independent in the normal state and vanishes in the superconducting state. The relaxation times of the BaO and SrO planar oxygens, as well as of the TlO planar oxygens, are much longer than those of the CuO2 planes, and are similar to the values found for the bismuthate and plumbate materials. In both lanthanum cuprates, the frequency shift of the CuO2 plane is temperature dependent in the normal state. Relaxation-rate data, when plotted as a function of ln(Tc), show a clear difference between the bismuthate (plumbate) and cuprate materials, and appear consistent with BCS-like behavior for the copper-free systems.
AB - We have measured the O17 nuclear-magnetic-resonance spin-lattice relaxation times (T1) as a function of temperature for the CuO2 planar sites in Tl2Ba2CaCu2O8+x, YBa2Cu3O7-x, Bi2Sr2CaCu2O8+x, La1.85Sr0.15CuO4-x, La1.85Ca0.15CuO4-x, and Bi2Sr2CuO6+x, as well as for the oxygen sites in Ba0.6K0.4BiO3, BaBi0.25Pb0.75O3, BaSb0.25Pb0.75O3, and BaPbO3. The CuO2 planar sites in Tl2Ba2CaCu2O8+x, YBa2Cu3O7-x, and Bi2Sr2CaCu2O8+x exhibit close to ideal Korringa behavior in the normal state, characteristic of a good metal. In addition, the Knight shift of the CuO2 planes in these three materials is dominated by a spin contribution that is temperature independent in the normal state and vanishes in the superconducting state. The relaxation times of the BaO and SrO planar oxygens, as well as of the TlO planar oxygens, are much longer than those of the CuO2 planes, and are similar to the values found for the bismuthate and plumbate materials. In both lanthanum cuprates, the frequency shift of the CuO2 plane is temperature dependent in the normal state. Relaxation-rate data, when plotted as a function of ln(Tc), show a clear difference between the bismuthate (plumbate) and cuprate materials, and appear consistent with BCS-like behavior for the copper-free systems.
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U2 - 10.1103/PhysRevB.43.10466
DO - 10.1103/PhysRevB.43.10466
M3 - Article
AN - SCOPUS:0001353593
SN - 0163-1829
VL - 43
SP - 10466
EP - 10471
JO - Physical Review B
JF - Physical Review B
IS - 13
ER -