Modification of perhydropolysilazane with aluminum hydride: Preparation of poly(aluminasilazane)s and their conversion into Si–Al–N–C ceramics

Microstructure and thermal stability of amorphous SiBCNAl powders fabricated by mechanical alloying

“…The 100 ppm signal corresponds to tetrahedral AlN 4 sites [29], implying the presence of AlN in the as-milled powders. The position of the resonance at 57 ppm may be assigned to the mixed local chemical environment of the aluminium nuclei corresponding to pentahedral AlN 5 and/or tetrahedral AlO 4 units [30,31]. A small peak at 4 ppm should be responded to octahedral AlN 6 units [31].…”

Nanocomposites through the Chemistry of Single‐Source Precursors: Understanding the Role of Chemistry behind the Design of Monolith‐Type Nanostructured Titanium Nitride/Silicon Nitride

“…The 29 Si MAS NMR spectrum of PHPTiS2.5 (Figure 4b) exhibits ab road line with am aximum at around d = À36 ppm assigned to both N 2 SiH 2 and N 3 SiHe nvironments. [38] Their presence highlights the reactions between SiH units and N(CH 3 ) 2 groups. The small signal at around d = À48 ppm in all samples, attributed to SiN 4 groups, definitely confirms the occurrenceofthis reaction.…”

Structural and microstructural characterization of SiB0.5C1.5N0.8Al0.3 powders prepared by mechanical alloying using aluminum nitride as aluminum source

“…After milling, the 27 Al chemical shifts of SiB 0.5 C 1.5 N 0.8 Al 0.3 powders are at 112.9 and 57.0 ppm corresponding to the AlN 4 and AlN 5 units, respectively (as shown in Fig. 3(c)) [13]. The result indicates that the local environment around the aluminum atoms changes from AlN 4 to the mixture of AlN 4 and AlN 5 by mechanical alloying.…”

“…The signal at 112.8 ppm suggests that the environment of aluminum atoms is tetrahedral AlN 4 sites in the starting AlN powders (as shown in Fig. 3(b)) [13]. After milling, the 27 Al chemical shifts of SiB 0.5 C 1.5 N 0.8 Al 0.3 powders are at 112.9 and 57.0 ppm corresponding to the AlN 4 and AlN 5 units, respectively (as shown in Fig.…”