From Framework to Layers Driven by Pressure – The Monophyllo‐Oxonitridophosphate β‐MgSrP<sub>3</sub>N<sub>5</sub>O<sub>2</sub> and Comparison to its α‐Polymorph
Reinhard M. Pritzl, N. Prinz, Philipp Strobel, Peter J. Schmidt, Dirk Johrendt, Wolfgang Schnick
Abstract
Abstract Oxonitridophosphates exhibit the potential for broad structural diversity, making them promising host‐compounds in phosphor‐converted light‐emitting diode applications. The novel monophyllo‐oxonitridophosphate β‐MgSrP 3 N 5 O 2 was obtained by using the high‐pressure multianvil technique. The crystal structure was solved and refined based on single‐crystal X‐ray diffraction data and confirmed by powder X‐ray diffraction. β‐MgSrP 3 N 5 O 2 crystallizes in the orthorhombic space group Cmme (no. 67, a =8.8109(6), b =12.8096(6), c =4.9065(3) Å, Z= 4) and has a structure related to that of Ba 2 CuSi 2 O 7 . DFT calculations were performed to investigate the phase transition from α‐ to β‐MgSrP 3 N 5 O 2 and to confirm the latter as the corresponding high‐pressure polymorph. Furthermore, the luminescence properties of Eu 2+ doped samples of both polymorphs were investigated and discussed, showing blue and cyan emission, respectively (α‐MgSrP 3 N 5 O 2 ; λ max =438 nm, fwhm =46 nm/2396 cm −1 ; β‐MgSrP 3 N 5 O 2 ; λ max =502 nm, fwhm =42 nm/1670 cm −1 ).