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Novel Composite Nitride Nanoceramics from Reaction-Mixed Nanocrystalline Powders in the System Aluminum Nitride AlN/Gallium Nitride GaN/Titanium Nitride TiN (Al:Ga:Ti = 1:1:1)
| Content Provider | MDPI |
|---|---|
| Author | Drygas, Mariusz Lejda, Katarzyna Janik, Jerzy F. Stelmakh, Svitlana Palosz, Bogdan |
| Copyright Year | 2022 |
| Description | A study is presented on the synthesis of reaction-mixed nitride nanopowders in the reference system of aluminium nitride AlN, gallium nitride GaN, and titanium nitride TiN (Al:Ga:Ti = 1:1:1) followed by their high-pressure and high-temperature sintering towards novel multi-nitride composite nanoceramics. The synthesis starts with a 4 h reflux in hexane of the mixture of the respective metal dimethylamides, which is followed by hexane evacuation, and reactions of the residue in liquid ammonia at −33 °C to afford a mixed metal amide/imide precursor. Plausible equilibration towards a bimetallic Al/Ga-dimethylamide compound upon mixing of the solutions of the individual metal-dimethylamide precursors containing dimeric ${Al[N(CH_{3})_{2}]_{3}}_{2}$ and dimeric ${Ga[N(CH_{3})_{2}]_{3}}_{2}$ is confirmed by$ ^{1}$H- and$ ^{13}$C{H}-NMR spectroscopy in $C_{6}D_{6}$ solution. The precursor is pyrolyzed under ammonia at 800 and 950 °C yielding, respectively, two different reaction-mixed composite nitride nanopowders. The latter are subjected to no-additive high-pressure and high-temperature sintering under conditions either conservative for the initial powder nanocrystallinity (650 °C, 7.7 GPa) or promoting crystal growth/recrystallization and, possibly, solid solution formation via reactions of AlN and GaN towards $Al_{0.5}Ga_{0.5}$N (1000 and 1100 °C, 7.7 GPa). The sintered composite pellets show moderately high mechanical hardness as determined by the Vicker’s method. The starting nanopowders and resulting nanoceramics are characterized by powder XRD, Raman spectroscopy, and SEM/EDX. It is demonstrated that, in addition to the multi-nitride composite nanoceramics of hexagonal AlN/hexagonal GaN/cubic TiN, under specific conditions the novel composite nanoceramics made of hexagonal $Al_{0.5}Ga_{0.5}$N and cubic TiN can be prepared. |
| Starting Page | 2200 |
| e-ISSN | 19961944 |
| DOI | 10.3390/ma15062200 |
| Journal | Materials |
| Issue Number | 6 |
| Volume Number | 15 |
| Language | English |
| Publisher | MDPI |
| Publisher Date | 2022-03-16 |
| Access Restriction | Open |
| Subject Keyword | Materials Ceramics Aluminium Nitride Aln Gallium Nitride Gan Aluminium Gallium Nitride Algan Titanium Nitride Tin Nanopowders Sintering Composites Nanoceramics |
| Content Type | Text |
| Resource Type | Article |
