Niewa, Rainer ; Rau, Dieter ; Wosylus, Aron ; Meier, Katrin ; Hanfland, Michael ; Wessel, Michael ; Dronskowski, Richard ; Dzivenko, Dmytro A. ; Riedel, Ralf ; Schwarz, Ulrich (2009)
High-Pressure, High-Temperature Single-Crystal Growth, Ab initio Electronic Structure Calculations, and Equation of State of ε-Fe3N1+x.
In: Chemistry of Materials, 21 (2)
doi: 10.1021/cm802721k
Artikel, Bibliographie
Kurzbeschreibung (Abstract)
The high-pressure behavior of the hard material ε-Fe3N1+x was studied up to 33 GPa with in situ X-ray diffraction experiments using diamond anvil cells in combination with synchrotron radiation as well as by ex situ high-temperature, high-pressure treatment at 1600(200) K in a two-stage multianvil device with a Walker-type module. Evaluation of the pressure−volume data up to 10 GPa by fitting a Murnaghan-type equation reveals a bulk modulus of B0 = 172(4) GPa (B′ = 5.7, fixed). The calculated bulk modulus (220 GPa) on the basis of density-functional theory (GGA-PAW-PBE) is in satisfying agreement with the experimental one. Single crystals of ε-Fe3N1+x as obtained by ex situ high-temperature, high-pressure experiments reveal in X-ray diffraction data refinements a structural model of iron atoms in the motif of a hexagonal close packing with occupation of octahedral voids by nitrogen atoms exhibiting long-range order. The preferred structural model is described in space group P312 (a = 4.7241(2) Å, c = 4.3862(2) Å, V = 84.773(6) Å3, Z = 2, R(F) = 0.0339, wR(F2) = 0.0556) and compared to a second model in P6322. This choice of structural description is corroborated by the results of density-functional calculations. These yield a total energy at 0 K, which is 5 kJ/mol lower for the model in space group P312 compared to the second best alternative arrangement. Using micro- and nanoindentation techniques, a Vickers hardness of HV = 7.4(10) GPa, a nanoindentation hardness of H = 10.1(8) GPa, as well as a reduced elastic modulus in the amount of Er = 178(11) GPa were measured for ε-Fe3N1+x single crystals.
| Typ des Eintrags: | Artikel |
|---|---|
| Erschienen: | 2009 |
| Autor(en): | Niewa, Rainer ; Rau, Dieter ; Wosylus, Aron ; Meier, Katrin ; Hanfland, Michael ; Wessel, Michael ; Dronskowski, Richard ; Dzivenko, Dmytro A. ; Riedel, Ralf ; Schwarz, Ulrich |
| Art des Eintrags: | Bibliographie |
| Titel: | High-Pressure, High-Temperature Single-Crystal Growth, Ab initio Electronic Structure Calculations, and Equation of State of ε-Fe3N1+x |
| Sprache: | Englisch |
| Publikationsjahr: | 27 Januar 2009 |
| Verlag: | ACS |
| Titel der Zeitschrift, Zeitung oder Schriftenreihe: | Chemistry of Materials |
| Jahrgang/Volume einer Zeitschrift: | 21 |
| (Heft-)Nummer: | 2 |
| DOI: | 10.1021/cm802721k |
| Kurzbeschreibung (Abstract): | The high-pressure behavior of the hard material ε-Fe3N1+x was studied up to 33 GPa with in situ X-ray diffraction experiments using diamond anvil cells in combination with synchrotron radiation as well as by ex situ high-temperature, high-pressure treatment at 1600(200) K in a two-stage multianvil device with a Walker-type module. Evaluation of the pressure−volume data up to 10 GPa by fitting a Murnaghan-type equation reveals a bulk modulus of B0 = 172(4) GPa (B′ = 5.7, fixed). The calculated bulk modulus (220 GPa) on the basis of density-functional theory (GGA-PAW-PBE) is in satisfying agreement with the experimental one. Single crystals of ε-Fe3N1+x as obtained by ex situ high-temperature, high-pressure experiments reveal in X-ray diffraction data refinements a structural model of iron atoms in the motif of a hexagonal close packing with occupation of octahedral voids by nitrogen atoms exhibiting long-range order. The preferred structural model is described in space group P312 (a = 4.7241(2) Å, c = 4.3862(2) Å, V = 84.773(6) Å3, Z = 2, R(F) = 0.0339, wR(F2) = 0.0556) and compared to a second model in P6322. This choice of structural description is corroborated by the results of density-functional calculations. These yield a total energy at 0 K, which is 5 kJ/mol lower for the model in space group P312 compared to the second best alternative arrangement. Using micro- and nanoindentation techniques, a Vickers hardness of HV = 7.4(10) GPa, a nanoindentation hardness of H = 10.1(8) GPa, as well as a reduced elastic modulus in the amount of Er = 178(11) GPa were measured for ε-Fe3N1+x single crystals. |
| Fachbereich(e)/-gebiet(e): | 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft > Fachgebiet Disperse Feststoffe 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft 11 Fachbereich Material- und Geowissenschaften |
| Hinterlegungsdatum: | 12 Apr 2012 08:27 |
| Letzte Änderung: | 05 Mär 2013 10:00 |
| PPN: | |
| Sponsoren: | This work was supported by the Elitenetzwerk Bayern within the Advanced Materials Science program, This work was supported by the Max-Planck-Gesellschaft, This work was supported within the priority program “Synthesis, in situ characterisation and quantum mechanical modelling of Earth Materials, oxides, carbides and nitrides at extremely high pressures and temperatures” of the D FG (SPP 1236) |
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