Ammonothermal Synthesis, Optical Properties, and DFT Calculations of Mg₂PN₃ and Zn₂PN₃

Abstract

The phosphorus nitrides, Mg PN and Zn PN , are wide band gap semiconductor materials with potential for application in (opto)electronics or photovoltaics. For the first time, both compounds were synthesized ammonothermally in custom-built high-temperature, high-pressure autoclaves starting from P N and the corresponding metals (Mg or Zn). Alkali amides (NaNH , KNH ) were employed as ammonobasic mineralizers to increase solubility of the starting materials in supercritical ammonia through formation of reactive intermediates. Single crystals of Mg PN , with length up to 30 μm, were synthesized at 1070 K and 140 MPa. Zn PN already decomposes at these conditions and was obtained as submicron-sized crystallites at 800 K and 200 MPa. Both compounds crystallize in a wurtzite-type superstructure in orthorhombic space group Cmc2 , which was confirmed by powder X-ray diffraction. In addition, single-crystal X-ray diffraction measurements of Mg PN were carried out for the first time. To our knowledge, this is the first single-crystal X-ray study of ternary nitrides synthesized by the ammonothermal method. The band gaps of both nitrides were estimated to be 5.0 eV for Mg PN and 3.7 eV for Zn PN by diffuse reflectance spectroscopy. DFT calculations were carried out to verify the experimental values. Furthermore, a dissolution experiment was conducted to obtain insights into the crystallization behavior of Mg PN .

Crystalline Nitridophosphates by Ammonothermal Synthesis

“…[17] In this contribution we report on the ammonothermal syntheses of a-Li 10 P 4 N 10 , b-Li 10 P 4 N 10 ,L i 18 P 6 N 16 ,C a 2 PN 3 ,S rP 8 N 14 ,a nd LiPN 2 .T hose compounds feature ad egree of condensation in ther ange 1/3 k 4/7 (Figure 4), corresponding to different types of anionic tetrahedra-baseds ubstructures, such as non-condensed tetrahedra groups, chains, layers and 3D-networks. [17] In this contribution we report on the ammonothermal syntheses of a-Li 10 P 4 N 10 , b-Li 10 P 4 N 10 ,L i 18 P 6 N 16 ,C a 2 PN 3 ,S rP 8 N 14 ,a nd LiPN 2 .T hose compounds feature ad egree of condensation in ther ange 1/3 k 4/7 (Figure 4), corresponding to different types of anionic tetrahedra-baseds ubstructures, such as non-condensed tetrahedra groups, chains, layers and 3D-networks.…”

“…[6][7][8][9] Recent explorative syntheses under ammonothermal conditions made crystalline wurtzite-type Grimm-Sommerfeld analogous nitrides available, such as InN, II-IV-N 2 compounds (II = Mg, Mn, Zn;I V = Si, Ge) and CaGaSiN 3 ,a sw ell as oxide nitride perovskites such as LnTaON 2 (Ln = La, Ce, Pr,N d, Sm, Gd). [16][17][18] Furthermore, various phosphoruscontaining imidonitrides were synthesized in supercritical ammonia and thus, the ammonothermal method appears as a promising general synthetic approachf or nitridophosphate synthesis. [16][17][18] Furthermore, various phosphoruscontaining imidonitrides were synthesized in supercritical ammonia and thus, the ammonothermal method appears as a promising general synthetic approachf or nitridophosphate synthesis.…”

Nitridophosphate – eine Erfolgsgeschichte der Nitridsynthese

“…[52][53][54][55][56] Der [47] Angewandte Chemie Kurzaufsätze Die Hochdrucktechniken waren der Schlüssel fürd ie große Zusammensetzungs-und Strukturvielfalt der Nitridophosphate,d an ach dem Prinzip von Le Chatelier hohe Drücke die Zersetzungstemperaturen der Ausgangsverbindungen erhçhen. Die Multianvil-Technik ist gegenwärtig Stand der Te chnik, da sie quasi-hydrostatische Druckverhältnisse und ein relativ großes Probenvolumen mit hohen Drücken von bis zu 25 GPa und Te mperaturen von bis zu 1800 8 8Cv ereint (Abbildung 9).…”

Nitridophosphates: A Success Story of Nitride Synthesis

“…[36,49] Since then, however, ammonothermal syntheses of nitridophosphates were not reported until they recently experienced ar enaissance because of the production of custom-built autoclaves from state-of-the-art nickel-based superalloys Inconel 718 (max. [47] Ther eaction mechanism is still under investigation. 800 8 8C, 0.17 GPa).…”

“…b) Scanning electron micrograph of Mg 2 PN 3 crystals grown by ammonothermal synthesis [47]. b) Scanning electron micrograph of Mg 2 PN 3 crystals grown by ammonothermal synthesis [47].…”