Phase relations of the Si3N4-AIN-CaO system

An analysis of crystal structure of Ca-deficient oxonitridoaluminosilicate, Ca0.88Al0.91Si1.09N2.85O0.15

“…To understand theoretically the unusual character of Eu 2+ is possible by studying which environments Eu 2+ has in the crystal. CaAlSiN3 has already been reported by Huang et al, 4) however, they only indexed it in an orthorhombic unit cell with a = 562.9pm, b = 958.4pm, and c = 498.6pm. The crystal structure of CaAlSiN3 was not solved in this report.…”

“…(unsure if this is what author is trying to convey) Keeping the symmetry of 21 screw axis, these sheets were stacked along the c-axis to build up a three dimensional structure Ca0.88Al0.91Si1.09N2.85O0.15 is considered to be a solid solution by mixing CaAlSiN3 and Si2N2O. In the report by Huang et al, 4) CaAlSiN3 and AlN existed in a wider range in the system, 3CaO·Si2N2O-2CaO·Si3N4-AlN, above 1500C, and the lattice parameters were different from those reported by Ottinger and calculated in this report. Therefore, there are expected to be a wide variety of solid-solutions with defects between CaAlSiN3 and Si2N2O.…”

Low-temperature synthesis of CaAlSiN₃:Ce³⁺ using the ammonothermal method

“…The XRD patterns of all the products prepared using the different mineralizers agreed with the pattern for CaAlSiN 3 reported in the ICDD data 00-039-0747. 8) Using K or Ca, the Ca(OH) 2 peak was detected in the XRD patterns of the products. The diffraction peaks at 2ª = 28.6, 34.1, and 47.1°f rom Ca(OH) 2 crystal corresponded to Miller indices of (100), (101), and (102), respectively.…”

“…The XRD patterns of the products agreed with the pattern for CaAlSiN 3 reported in the ICDD data 00-039-0747. 8) The results of XRD analysis indicated that the optimal temperature for CaAlSiN 3 synthesis was 773 K because the sample treated at this temperature exhibited the highest diffraction intensity and the smallest half-value width. The full width at half maximum (FWHM) value of (002) line obtained at 573, 673, and 773 K are 0.47, 0.33, and 0.27°, respectively.…”

Effects of process on microstructure and properties of translucent Dy-.ALPHA.-SiAlON sintered at lower temperatures

“…Besides more extra energy supplied by high pressure and high temperature with HP, adding oxide sintering additive, especially rare earth oxides Ln2O3 (Ln = Nd, Sm, Gd, Dy, Y, Er and Yb), 7), 8) has been taken as another effective way to promote α-SiAlON densification in the past years. But, the sintering temperature still maintained very high for the Si3N4-solide solution system materials.…”