We report the first oxynitride of tin, Sn2N2O (SNO), exhibiting a Rh2S3‐type crystal structure with space group Pbcn. All Sn atoms are in six‐fold coordination, in contrast to Si in silicon oxynitride (Si2N2O) and Ge in the isostructural germanium oxynitride (Ge2N2O), which appear in four‐fold coordination. SNO was synthesized at 20 GPa and 1200–1500 °C in a large volume press. The recovered samples were characterized by synchrotron powder X‐ray diffraction and single‐crystal electron diffraction in the TEM using the automated diffraction tomography (ADT) technique. The isothermal bulk modulus was determined as Bo=193(5) GPa by using in‐situ synchrotron X‐ray diffraction in a diamond anvil cell. The structure model is supported by DFT calculations. The enthalpy of formation, the bulk modulus, and the band structure have been calculated.

Here we report on the discovery of a ternary silicon titanium nitride with the general composition (Si 1−x ,ti x) 3 n 4 with x = 0 < x < 1 and spinel-type crystal structure. The novel nitride is formed from an amorphous silicon titanium nitride (Sitin) precursor under high-pressure/high-temperature conditions in a large volume high-pressure device. Under the conditions of 15-20 GPa and 1800-2000 °C, spineltype γ-Si 3 n 4 and rock salt-type c-TiN are formed. In addition, crystals of the discovered nano-sized ternary phase (Si 1−x ,ti x) 3 n 4 embedded in γ-Si 3 n 4 are identified. The ternary compound is formed due to kinetically-controlled synthesis conditions and is analyzed to exhibit the spinel-type structure with ca. 8 atom% of Ti. The Ti atoms occur in both Ti 3+ and ti 4+ oxidation states and are located on the Si sites. the ternary nano-crystals have to be described as (Si,ti) 3 n 4 with n-vacancies resulting in the general composition (Si 4+ 1−x ti 4+ x-δ ti 3+ δ) 3 n 4-δ .

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High‐pressure synthesis of a tin oxynitride Sn2N2O (SNO) is described. A schematic drawing of the large volume press (LVP) (Max Voggenreiter GmbH, mavo press LPQ6‐1500‐100) installed at beamline P61B, PETRA III, DESY, Hamburg is presented along with the high‐pressure anvil assembly at extreme conditions. The SNO crystal structure (space group: Pbcn) of Rh2S3‐type with all Sn atoms in six‐fold coordination is also highlighted [Picture Credit: Stefan Sonntag; Shrikant Bhat @DESY]. For more information see the Full Paper by S. Bhat et al. on page 2187 ff.