Synthesis, Structure and Properties of Layered Phosphide Nitrides AkTh2Mn4P4N2 (Ak = Rb, Cs)†

Main observation and conclusion We report the design, synthesis, structure, and properties of two complex layered phosphide nitrides, AkTh(2)Mn(4)P(4)N(2) (Ak = Rb, Cs), which contain anti-fluorite-type [Mn2P2] bilayers separated by fluorite-type [Th2N2] layers as a result of the intergrowth between AkMn(2)P(2) and ThMnPN. The new compounds are featured with an intrinsic hole doping associated with the interlayer charge transfer and a built-in chemical pressure from the [Th2N2] layers, both of which are reflected by the changes in the lattice and the atomic position of phosphorus. The measurements of magnetic susceptibility, electrical resistivity, and specific heat indicate existence of local moments as well as itinerant electrons in relation with d-p hybridizations. The expected dominant antiferromagnetic interactions with enhanced d-p hybridizations were demonstrated by the first-principles calculations only when additional Coulomb repulsions are included. The density of states at the Fermi level derived from the specific-heat analysis are 3.5 and 7.5 times of the calculated ones for Ak = Rb and Cs, respectively, suggesting strong electron correlations in the title compounds.

Automated summary

The study reports the design, synthesis, structure, and properties of two complex layered phosphide nitrides, highlighting the significant antiferromagnetic interactions and strong electron correlations present in the compounds. Properties such as interlayer charge transfer and built-in chemical pressure from specific layers have effects on the lattice and atomic positions of phosphorus in the compounds. There are both local moments and itinerant electrons present in the compounds, with dominant antiferromagnetic interactions shown in first-principles calculations when additional Coulomb repulsions are considered.