Synthesis, Structure, and Properties of a New Ternary Metal Nitride, Ca3CrN3

摘要

We have synthesized a new ternary nitride, Ca3CrN3 (calcium chromium nitride),from the binary nitrides at high temperature. The refined structure was solved in the Cmcm space group with lattice constants a=8.503(2), b=10.284(2), c=5.032(1), and R=3.9%, R(w)=3.9%. This new structure type consists of sheets of (CrN3)6(-) planar triangular units and calcium ions. Ca3CrN3 is insulating and paramagnetic with Cr3(+) in the low spin state. This is the first unambiguous example of low spin Cr3(+). Larger than expected antiferromagnetic interactions produce a maximum in the magnetic susceptibility at 245K, even though the shortest Cr-Cr distance is 4.73A. Solid state nitrides, Crystal structure, Magnetic properties, Low dimensional compounds, Triangular planar units, Paramagnetic insulator, Solid state chemistry. (jg)