Subsolidus Phase Relationships in Si₃N₄–AlN–Rare‐Earth Oxide Systems

Abstract

Powders of silicon nitride, aluminum nitride, and rare-earth oxides were weighed and mixed in an agate jar under absolute ethyl alcohol on a rotating mill for 2 h. Dried mixtures were hotmessed at 1700°C

Study on the stability of Ce α-Sialon derived from SHS-ed powder

“…In conventional synthesis methods, these cations include Li + , Mg 2+ , Ca 2+ , Y 3+ and some lanthanides ions with exception of Ce 3+ , Pr 3+ and Eu 3+ . 2,3 However, attention to a 0 stabilized by rare earth ions that could not be absorbed into a 0 structure by conventional synthesis, such as Ce 3+ , has been paid in the last two decades. 4À11 Studies by Ekstro¨m and co-workers on the sintering of Sialon ceramics showed that a small amount of cerium ions can be incorporated into the large interstitial holes of a 0 structure if yttrium is added as additive simultaneously.…”

Facile synthesis of Ca-α-SiAlON:Eu2+ phosphor by the microwave sintering method and its photoluminescence properties

“…-SiAlONs are solid solution compounds derived from -Si 3 N 4 with partial replacement of Si 4+ by Al 3+ and N 3− by O 2− , having an overall composition in the formula M x Si 12−(m+n) Al m+n O n N 16−n (x=m/v, v is the valence of metal M) with M=Li, Ca, Mg, Y, and rare earth [1][2][3]. The valence balance is achieved by introducing cations M into large interstices available in the network of (Si, Al)-(O, N).…”

Fine yellowα-SiAlON:Eu phosphors for white LEDs prepared by the gas-reduction–nitridation method

“…There are two interstitial sites per unit cell in the a-Si 3 N 4 structure that can be occupied by Me p+ metal ions, which limits the maximum value of x to 2 in formula (1), because each unit cell contains four formula units. The Me elements that have been reported to stabilize the a-SiAlON structure are Li, Mg, Ca, Y and the rare-earth metals except for Ce, La, Pr and Eu [1][2][3][4]. Generally, it is impossible to stabilize the a-SiAlON structure for rare-earth metals with a large ionic size such as Eu 2+ and Ce 3+ , but it is possible if they are codoped with calcium [5,6].…”