Solid Solutions of Grimm-Sommerfeld Analogous Nitride Semiconductors II-IV-N (II=Mg, Mn, Zn; IV=Si, Ge): Ammonothermal Synthesis and DFT Calculations.

Grimm-Sommerfeld analogous II-IV-N nitrides such as ZnSiN , ZnGeN , and MgGeN are promising semiconductor materials for substitution of commonly used (Al,Ga,In)N. Herein, the ammonothermal synthesis of solid solutions of II-IV-N compounds (II=Mg, Mn, Zn; IV=Si, Ge) having the general formula (II II )-IV-N with x≈0.5 and ab initio DFT calculations of their electronic and optical properties are presented.

Ab initio exploration and prediction of AE-containing nitrido(litho/magneso)tetrelates (AE = Ca, Sr; Tt = Si, Ge) with [SiN] or [GeN] units.

Recently, a number of different structurally related nitrides characterized by pairs of edge-sharing Si-N tetrahedra forming [SiN] units have emerged via different synthesis methods. Concurrently, upon doping with rare earth elements (e.g.

Orange-Emitting LiSr[SiON]O:Eu-a Layered Lithium Oxonitridosilicate Oxide.

We report on the structure and properties of the lithium oxonitridosilicate oxide LiSr[SiON]O:Eu obtained from solid-state metathesis. The crystal structure was solved and refined from single-crystal X-ray data in the space group P4/ nmc (No. 137) [ Z = 2, a = 7.

Ammonothermal Synthesis, Optical Properties, and DFT Calculations of Mg PN and Zn PN.

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.

Oxoberyllates SrBeO and Sr Be O as Novel Host Materials for Eu Luminescence.

Beryllate structures are marginally investigated, but show intriguing structural relations to oxo- and nitridosilicates. A typical feature is the coordination of Be in both trigonal planar and tetrahedral coordination by O. A broad range of structures is accessible by variable combinations of both building units.

Stishovite's Relative: A Post-Coesite Form of Phosphorus Oxonitride.

Phosphorus oxonitride (PON) is isoelectronic with SiO and may exhibit a similar broad spectrum of intriguing properties as silica. However, PON has only been sparsely investigated under high-pressure conditions and there has been no evidence on a PON polymorph with a coordination number of P greater than 4. Herein, we report a post-coesite (pc) PON polymorph exhibiting a stishovite-related structure with P in a (5+1) coordination.

Ammonothermal Synthesis and Optical Properties of Ternary Nitride Semiconductors Mg-IV-N , Mn-IV-N and Li-IV -N (IV=Si, Ge).

Grimm-Sommerfeld analogous nitrides MgSiN , MgGeN , MnSiN , MnGeN , LiSi N and LiGe N (generally classified as II-IV-N and I-IV -N ) are promising semiconductor materials with great potential for application in (opto)electronics or photovoltaics. A new synthetic approach for these nitride materials was developed using supercritical ammonia as both solvent and nitride-forming agent. Syntheses were conducted in custom-built high-pressure autoclaves with alkali metal amides LiNH , NaNH or KNH as ammonobasic mineralizers, which accomplish an adequate solubility of the starting materials and promote the formation of reactive intermediate species.

Reversible Polymerization of Adamantane-type [P N ] Anions to Honeycomb-type [P N ] Layers under High-Pressure.

The high-pressure polymorph Li P N of Li P N (="2 Li P N ") was synthesized by high-pressure/high-temperature reaction of LiPN and Li PN or β-Li P N at 9 GPa, using the Li N self-flux method in a Walker-type multianvil assembly. Li P N is the first lithium nitridophosphate with a layered structure and is made up of corner sharing PN tetrahedra forming a corrugated honeycomb-type layer of linked sechser-rings in chair conformation. The arrangement of the P atoms is analogous to that of black phosphorus.

Li P N with Non-Condensed [P N ] -Rings and its High-Pressure Polymorph Li PN with Infinite Chains of PN -Tetrahedra.

Li P N was synthesized by solid-state reaction of Li N and P N at 790 °C. It is made up of non-condensed [P N ] dreier-rings of PN -tetrahedra. The corresponding high-pressure polymorph, Li PN , was synthesized under high-pressure/high-temperature conditions from Li P N or LiPN and Li PN at 6 or 7 GPa, respectively, using the multianvil technique.

First-principles and experimental characterization of the electronic properties of CaGaSiN and CaAlSiN: the impact of chemical disorder.

We report a detailed investigation of the electronic, mechanical and optical properties of the recently discovered nitridogallosilicate CaGaSiN which has potential as a LED-phosphor host material. We focus on chemical disorder effects, originating from the Ga/Si site, and compared them to those of isostructural CaAlSiN. We calculate the elastic moduli and the Debye temperature in terms of quasi harmonical approximation.

Ammonothermal Synthesis of Novel Nitrides: Case Study on CaGaSiN.

The first gallium-containing nitridosilicate CaGaSiN was synthesized in newly developed high-pressure autoclaves using supercritical ammonia as solvent and nitriding agent. The reaction was conducted in an ammonobasic environment starting from intermetallic CaGaSi with NaN as a mineralizer. At 770 K, intermediate compounds were obtained, which were subsequently converted to the crystalline nitride at temperatures up to 1070 K (70-150 MPa).

High-Pressure Synthesis of Melilite-type Rare-Earth Nitridophosphates RE2P3N7 and a Ba2Cu[Si2O7]-type Polymorph.

High-pressure metathesis was proposed to be a gateway to the elusive class of rare-earth nitridophosphates. With this method the first ternary compounds of this class with sum formula RE2P3N7 were prepared, a melilite-type with RE = Pr, Nd, Sm, Eu, Ho, Yb (Ho2P3N7: P4̅21m, a = 7.3589(2), c = 4.

A high-pressure polymorph of phosphorus oxonitride with the coesite structure.

The chemical and physical properties of phosphorus oxonitride (PON) closely resemble those of silica, to which it is isosteric. A new high-pressure phase of PON is reported herein. This polymorph, synthesized by using the multianvil technique, crystallizes in the coesite structure.