Equation of state for Eu-doped SrSi2O2N2

Abstract

α-SrSi2O2N2 is one of the recently studied oxonitridosilicates applicable in optoelectronics, in particular in white LEDs. Its elastic properties remain unknown. A survey of literature shows that, up to now, nine oxonitridosilicate materials have been identified. For most of these compounds, doped with rare earths and manganese, a luminescence has been reported at a wavelength characteristic for the given material; all together cover a broad spectral range. The present study focuses on the elastic properties of one of these oxonitridosilicates, the Eu-doped triclinic α-SrSi2O2N2. High-pressure powder diffraction experiments are used in order to experimentally determine, for the first time, the equation of state of this compound. The in situ experiment was performed for pressures ranging up to 9.65 GPa, for Eu-doped α-SrSi2O2N2 sample mounted in a diamond anvil cell ascertaining the hydrostatic compression conditions. The obtained experimental variation of volume of the triclinic unit cell of α-SrSi2O2N2:Eu with rising pressure served for determination of the Birch-Murnaghan equation of state. The determined above quoted bulk modulus is 103(5) GPa, its first derivative is 4.5(1.1). The above quoted bulk modulus value is found to be comparable to that of earlier reported oxynitrides of different composition.

Understanding Thermal Quenching of Photoluminescence in Oxynitride Phosphors from First Principles

“…However, experimental evidence 10,12,18,50 suggest that the substituted Eu 2+ atoms are randomly distributed across all substitution sites (may it be with uneven probability density). As already mentioned in Section 3.2, we attribute such random distribution of the Eu atoms substitution to the high firing temperature and the fact that Ba 2+ atoms form layers in BSON crystals.…”

A first-principles study of the electronic structure and mechanical and optical properties of CaAlSiN3

“…We can see from this table that the differences among the bulk moduli of the three phases as well as the shear moduli are comparatively small, and all the bulk moduli for three phases are large. A comparison with bulk moduli of 103(5) GPa for SrSi 2 O 2 N 2 :Eu, which shows valuable luminescence properties, 33 suggests that CaAlSiN 3 might be a relatively hard material. In addition, we can see that B H is larger than G H , which implies that the shear moduli G H limit the stability of these phases.…”

Structural phase transitions and photoluminescence properties of oxonitridosilicate phosphors under high hydrostatic pressure

“…X-ray diffraction study of (Sr 0.98 Eu 0.02 )Si 2 O 2 N 2 under hydrostatic pressure has shown that in pressure range up to 96.5 kbar triclinic structure was conserved23. The main motivation on performing high hydrostatic pressure was to investigate whether high pressure influences the structural stability of (Sr 0.98-x Ba x Eu 0.02 )Si 2 O 2 N 2 (0 < x ≤ 0.98) to induce phase transitions.…”