Abstract
The local distribution of electrons and holes in the plane of the high-temperature superconducting cuprates is determined with nuclear magnetic resonance through the quadrupole splittings of and . Based on new data for single crystals of electron-doped , 0.05, 0.10, 0.15) as well as , 0.13) the changes in hole contents of Cu and of O orbitals are determined and these account for the stoichiometrically doped charges, similar to hole-doped . It emerges that while in all parent materials as expected, and vary substantially between different groups of materials. Doping holes increases predominantly , but also . To the contrary, doping electrons predominantly decreases and only slightly . However, for the electron-doped systems is higher than that in hole-doped . Cuprates with the highest maximum 's appear to have a comparatively low and high . The rather high oxygen hole content of the and with the low seems to make them ideal candidates for hole doping to obtain a potentially high .
- Received 21 March 2014
- Revised 1 October 2014
DOI:https://doi.org/10.1103/PhysRevB.90.140504
©2014 American Physical Society