Abstract
We report a detailed study of the and NMR spin-lattice relaxation rates and the Knight shift (K) in The evolution of and K with x is in excellent agreement with the prediction of ab initio calculations of a highly anisotropic Fermi surface, consisting mainly of hole-type two-dimensional (2D) cylindrical sheets from bonding boron orbitals. The density of states at the Fermi level also decreases sharply on Al doping and the 2D sheets collapse at where the superconducting phase disappears.
- Received 23 September 2002
DOI:https://doi.org/10.1103/PhysRevB.66.140514
©2002 American Physical Society