| Abstract
| - Powder neutron diffraction experiments and DFT calculations rationalize the unexpected metallic properties of SrTiN2, demonstrating strong Ti−N covalency and that Sr−N interactions are central in the bonding description.
- The crystal chemistry and electronic structure of the layered nitride SrTiN2 have beenstudied by powder neutron diffraction (PND) and density functional methods, respectively.PND investigations at room temperature, 80 K, and 2 K show that the tetragonal KCoO2structure (space group P4/nmm (No. 129), a = 3.8823(1) Å, c = 7.7008(1) Å, V = 116.068(1)Å3, Z = 2 at 298 K) is retained across the temperature range and confirm the structuralmodel from previous room-temperature powder X-ray diffraction (PXD) studies. Furthermore,and importantly, PND data demonstrate that neither nitrogen nonstoichiometry norsubstitution of O2- for N3- within the anion sublattice is a plausible mechanism for holegeneration. Density functional calculations show that strong covalent bonding occurs withinthe TiN2 layers and that Sr−N interactions are pivotal in determining the band structureat the Fermi level. Calculations predict metallic and paramagnetic behavior for SrTiN2. Thesefindings are confirmed by experimental measurements.
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