Planar CuO2 hole density in high-Tc cuprates determined by NMR Knight shift: Cu63 NMR on bilayered Ba2CaCu2O4(F,O)2 and three-layered Ba2Ca2Cu3O6(F,O)2
Abstract
We report that planar CuO2 hole densities in high-Tc cuprates are consistently determined by the Cu NMR Knight shift. In single- and bilayered cuprates, it is demonstrated that the spin part of the Knight shift Ks(300 K) at room temperature monotonically increases with the hole density p from the underdoped to overdoped regions, suggesting that the relationship of Ks(300 K) vs p is a reliable measure to determine p. The validity of this Ks(300 K)-p relationship is confirmed by the investigation of the p dependencies of hyperfine magnetic fields and of spin susceptibility for single- and bilayered cuprates with tetragonal symmetry. Moreover, the analyses are compared with NMR data on three-layered Ba2Ca2Cu3O6(F,O)2 and HgBa2Ca2Cu3O8+δ and five-layered HgBa2Ca4Cu5O12+δ, which suggests the general applicability of the Ks(300 K)-p relationship to multilayered compounds with more than three CuO2 planes. The measurement of Ks(300 K) enables us to separately estimate p for each CuO2 plane in multilayered compounds, where doped hole carriers are inequivalent between outer CuO2 planes and inner CuO2 planes.
- Publication:
-
Physical Review B
- Pub Date:
- April 2011
- DOI:
- 10.1103/PhysRevB.83.144523
- arXiv:
- arXiv:1103.3407
- Bibcode:
- 2011PhRvB..83n4523S
- Keywords:
-
- 74.72.Gh;
- 74.62.-c;
- 74.25.nj;
- Transition temperature variations;
- Condensed Matter - Superconductivity
- E-Print:
- 7 pages, 5 figures, 2 Tables, to be published in Physical Review B