Abstract
Two rare earth iron aluminum silicides, REFe4Al 9Si6 (RE = Tb, Er), were synthesized in liquid Al at temperatures below 850°C. They crystallize in the tetragonal space group P42/nmc (no. 137) with cell dimensions of a = 8.718(1) Å and c = 15.171(3) Å for the Tb analogue. The structure, which is highly intricate and represents a rare structural arrangement, is based on that of NdRh4Al15.4. It can be understood in terms of highly corrugated layers of merged Al6 rings stacking to form a three-dimensional framework. The Fe and Si atoms are situated in various sites in the framework. The RE atoms have a very high coordination number (20) and sit in remaining pockets formed by the bonding arrangements in the structure. Magnetic measurements show that the rare earth ions are in a 3+ state, whereas Mössbauer measurements show that the Fe atoms do not exhibit a magnetic moment and are more reduced than in elemental Fe. The possible insights gained from these results into the metallurgical processing of advanced aluminum matrix alloys are discussed. Thermal gravimetric analysis experiments in air show that REFe4Al9Si6 is resistant to oxidation up to 900°C, which is attributable to an alumina/silica surface scale.
| Original language | English |
|---|---|
| Pages (from-to) | 6107-6115 |
| Number of pages | 9 |
| Journal | Chemistry of Materials |
| Volume | 20 |
| Issue number | 19 |
| DOIs | |
| Publication status | Published - Oct 14 2008 |
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ASJC Scopus subject areas
- Materials Chemistry
- Chemical Engineering(all)
- Chemistry(all)
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Al flux synthesis of the oxidation-resistant quaternary phase REFe 4Al9Si6 (RE = Tb, Er). / Sieve, Bradley; Gray, Danielle L.; Henning, Robert; Bakas, Thomas; Schultz, Arthur J.; Kanatzidis, Mercouri G.
In: Chemistry of Materials, Vol. 20, No. 19, 14.10.2008, p. 6107-6115.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Al flux synthesis of the oxidation-resistant quaternary phase REFe 4Al9Si6 (RE = Tb, Er)
AU - Sieve, Bradley
AU - Gray, Danielle L.
AU - Henning, Robert
AU - Bakas, Thomas
AU - Schultz, Arthur J.
AU - Kanatzidis, Mercouri G
PY - 2008/10/14
Y1 - 2008/10/14
N2 - Two rare earth iron aluminum silicides, REFe4Al 9Si6 (RE = Tb, Er), were synthesized in liquid Al at temperatures below 850°C. They crystallize in the tetragonal space group P42/nmc (no. 137) with cell dimensions of a = 8.718(1) Å and c = 15.171(3) Å for the Tb analogue. The structure, which is highly intricate and represents a rare structural arrangement, is based on that of NdRh4Al15.4. It can be understood in terms of highly corrugated layers of merged Al6 rings stacking to form a three-dimensional framework. The Fe and Si atoms are situated in various sites in the framework. The RE atoms have a very high coordination number (20) and sit in remaining pockets formed by the bonding arrangements in the structure. Magnetic measurements show that the rare earth ions are in a 3+ state, whereas Mössbauer measurements show that the Fe atoms do not exhibit a magnetic moment and are more reduced than in elemental Fe. The possible insights gained from these results into the metallurgical processing of advanced aluminum matrix alloys are discussed. Thermal gravimetric analysis experiments in air show that REFe4Al9Si6 is resistant to oxidation up to 900°C, which is attributable to an alumina/silica surface scale.
AB - Two rare earth iron aluminum silicides, REFe4Al 9Si6 (RE = Tb, Er), were synthesized in liquid Al at temperatures below 850°C. They crystallize in the tetragonal space group P42/nmc (no. 137) with cell dimensions of a = 8.718(1) Å and c = 15.171(3) Å for the Tb analogue. The structure, which is highly intricate and represents a rare structural arrangement, is based on that of NdRh4Al15.4. It can be understood in terms of highly corrugated layers of merged Al6 rings stacking to form a three-dimensional framework. The Fe and Si atoms are situated in various sites in the framework. The RE atoms have a very high coordination number (20) and sit in remaining pockets formed by the bonding arrangements in the structure. Magnetic measurements show that the rare earth ions are in a 3+ state, whereas Mössbauer measurements show that the Fe atoms do not exhibit a magnetic moment and are more reduced than in elemental Fe. The possible insights gained from these results into the metallurgical processing of advanced aluminum matrix alloys are discussed. Thermal gravimetric analysis experiments in air show that REFe4Al9Si6 is resistant to oxidation up to 900°C, which is attributable to an alumina/silica surface scale.
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U2 - 10.1021/cm801554d
DO - 10.1021/cm801554d
M3 - Article
VL - 20
SP - 6107
EP - 6115
JO - Chemistry of Materials
JF - Chemistry of Materials
SN - 0897-4756
IS - 19
ER -