Alkaline‐earth Metal Nitrides of the Main‐Group Elements: Crystal Structures and Properties of Inverse Perovskites

Abstract

Abstract. The knowledge on alkaline-earth metal nitrides of maingroup elements with Perovskite structures of the general composition (A 3 N x )E is reviewed. Compounds with closely related crystal structures denoted as Ruddlesden-Popper-Series are also taken into account. In a

Ammonothermal Synthesis of the Mixed‐Valence Nitrogen‐Rich Europium Tantalum Ruddlesden‐Popper Phase EuIIEuIII2Ta2N4O3

“…Subsequently, the autoclave was heated to the respective reaction temperature within 6 h and kept at this temperature for 110 h. The pressure slowly decreased over time because of hydrogen loss of the autoclave. Further details of the used autoclaves can be found in literature , , , …”

“…Further details of the used autoclaves can be found in literature. [2,3,[5][6][7]36,[76][77][78][79][80][81][82][83][84] Single-Crystal X-ray Diffraction X-ray diffraction data of Eu 3 Ta 2 N 4 O 3 were obtained by microfocus synchrotron diffraction (beamline ID11, ESRF, Grenoble) [85] on a Huber diffractometer (λ = 0.30996 Å) with a FReLoN2K CCD detector. [86] A crystallite that had been pre-characterized by TEM methods (see below) was used.…”

“…DFT calculations revealed that layered structures like Sr 2 TaNO 3 could exhibit promising photocatalytic activities . As with the perovskites, there are inverse representatives of Ruddlesden‐Popper phases like Ca 7 (Li 1– x Fe x )Te 2 N 2 and ( A 3 n +1 N n –1 O)Bi n+1 with A = Sr, Ba and n = 1, 3 . However, these compounds have relatively low nitrogen content.…”

Metal‐Rich Ternary Perovskite Nitrides

“…[20][21][22][23][24][25] The compounds (Ba 3 N)E with the larger E = Sb, Bi crystallize in the hexagonal 2H-perovskite variant (BaNiO 3 structure type, see Figure 3), although the Goldschmidt tolerance factor should even decrease compared to the respective cubic strontium or calcium compounds. [12,26] A reason for a stabilization of the hexagonal structure variant for particularly the barium compounds may be seen in a local shielding of the Coulomb repulsion between the alike charged nitride ions within face-sharing octahedral by the larger and softer (according to HSAB concept) barium ions. Still, in the crystal structures, these octahedra Ba 6 N are elongated parallel to [001].…”

The Inverse Perovskite Nitrides (Sr3N2/3–x)Sn, (Sr3N2/3–x)Pb, and (Sr3N)Sb: Flux Crystal Growth, Crystal Structures, and Physical Properties

“…Turning to nitrides, the similarly charge balanced pnictides ( Ae 3 N) E (15) [ E (15) = P, As, Sb, Bi] exhibit structures from cubic via simple distortion variants to hexagonal perovskites again depending on the sizes of Ae 2+ and E 3– ions, with partial cationic order leading to hexagonal stacking variants for mixed alkaline earth metal compounds . Nitride perovskites of the tetrelides were originally discussed with composition (Ca 3 N) E (14), due to their rather high electronic conductivity, but for Ae = Sr, Ba and E = Sn, Pb were later shown to be better described as disordered nitrogen deficient cubic perovskites ( Ae 3 N 2/3 ) E (14), again retaining charge balance .…”