Abstract
We report a site-separated O-17 NMR study of the layered perovskite ruthenate Sr3Ru2O7, which exhibits nearly two-dimensional transport properties and itinerant metamagnetism at low temperatures. The local hole occupancies and the spin densities in the oxygen 2p orbitals are obtained by means of tight-binding analyses of electric field gradients and anisotropic Knight shifts. These quantities are compared with two other layered perovskite ruthenates: the two-dimensional paramagnet Sr2RuO4 and the three-dimensional ferromagnet SrRuO3. The hole occupancies at the oxygen sites are very large, about one hole per ruthenium atom. This is due to the strong covalent character of the Ru-O bonding in this compound. The magnitude of the hole occupancy might be related to the rotation or tilt of the RuO6 octahedra. The spin densities at the oxygen sites are also large, 20%-40% of the bulk susceptibilities, but in contrast to the hole occupancies, the spin densities strongly depend on the dimensionality. This result suggests that the density of states at the oxygen sites plays an essential role for the understanding of the complex magnetism found in the layered perovskite ruthenates.
Original language | English |
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Number of pages | 9 |
Journal | Physical Review. B, Condensed matter and materials physics |
Volume | 75 |
DOIs | |
Publication status | Published - Jan 2007 |
Keywords
- QUALITY SINGLE-CRYSTALS
- ELECTRONIC-STRUCTURE
- SPIN FLUCTUATIONS
- SUPERCONDUCTOR SR2RUO4
- SRRUO3
- METAMAGNETISM
- POWDER
- PLANES