Dilute magnetism and vibrational entropy in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mtext>Fe</mml:mtext></mml:mrow><mml:mn>2</mml:mn></mml:msub><mml:msub><mml:mrow><mml:mtext>Al</mml:mtext></mml:mrow><mml:mn>5</mml:mn></mml:msub></mml:mrow></mml:math>

Chi, Ji; Zheng, Xiang; Rodriguez, Sergio Y.; Li, Yang; Gou, Weiping; Goruganti, V.; Rathnayaka, K. D. D.; Ross, Joseph H.

doi:10.1103/physrevb.82.174419

Cited by 17 publications

(4 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Noteworthy, the values of T D found from the center shift for the FeAl(II) sample, hence the one with a slightly higher content of Al are by 10% higher than the corresponding ones revealed for the FeAl(I) sample. It should be also noticed that our values of T D agree well with the one found from heat capacity measurements for Fe 2 Al 5 [6,10], but they are significantly smaller than the Debye temperature of 668 K calculated for the Fe 2 Al 5 intermetallic compound [11]. It should be, however, mentioned that inconsistencies between values of T D for a given material as determined with different methods are known because, in general, shapes of phonon density of states (PDS) are not parabolic.…”

Section: Debye Temperaturesupporting

confidence: 89%

“…This above-mentioned variety of intermetallics and their structures gives a unique opportunity for experimentalists to study their properties with various methods and techniques. For theoreticians these aluminides are usable to validate their models and calculations e. g. Fe 2 Al 5 and Fe 4 Al 13 as quasicrystal approximants [5,6].…”

Section: Introductionmentioning

confidence: 99%

“…To our best knowledge, no results on similar studies were reported in the available literature. Merely, the Debye temperature can be compared with the one determined for  based on low temperature heat capacity measurements [6,10] as well as with that obtained using the first-principles calculations [11].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Mössbauer spectroscopic and XRD studies of two η-Fe2Al5 intermetallics

et al. 2021

View full text Add to dashboard Cite

Section: Debye Temperaturesupporting

confidence: 89%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Mössbauer spectroscopic and XRD studies of two η-Fe2Al5 intermetallics

et al. 2021

View full text Add to dashboard Cite

“…That is, they correspond to oscillations along the channels. These low-frequency modes are able to create an appreciable excess entropy at temperatures as low as 30 K. 21 Comparing the free energies with the weighted average of mC102 and tI6, we find that oC24 is stabilized for temperatures greater than 320 K.…”

Section: Vibrational and Configurational Free Energiesmentioning

confidence: 84%

Structure and stability of Al2Fe and Al5Fe2: First-principles total energy and phonon calculations

Mihalkovič

Widom

2012

Phys. Rev. B

View full text Add to dashboard Cite

We employ first-principles total energy and phonon calculations to address the structure and stability of Al 2 Fe and Al 5 Fe 2 . The observed structure of Al 2 Fe, which is reported as stable in the assessed Al-Fe phase diagram, is distinguished by an unusually low triclinic symmetry. The initial crystallographic structure determination additionally featured an unusual hole large enough to accommodate an additional atom. Our calculations indicate that the hole must be filled, but predict that the triclinic structure is unstable relative to a simpler tetragonal structure based on the prototype MoSi 2 . This tetragonal structure is interesting because it is predicted to be nonmagnetic, electrically insulating, and high density, while the triclinic structure is magnetic, metallic, and low density. We reconcile this seeming contradiction by demonstrating a high vibrational entropy that explains why the triclinic structure is stable at high temperatures. Finally, we note that orthorhombic Al 5 Fe 2 is also destabilized by the tetragonal structure but may be stabilized at high temperatures, again by vibrational entropy and partial occupancy associated with the diffusion of Al atoms along channels.

show abstract

Structural and Thermodynamic Properties of Filter Materials: A Raman and DFT Investigation

Kraus,

Brehm,

Himcinschi

et al. 2024

Springer Series in Materials Science

View full text Add to dashboard Cite

The contribution focuses on the accurate prediction of heat capacities for intermetallics, the estimation of reaction paths for coated and uncoated alumina foam filters in contact with metallic melts, and the investigation of thermally induced changes in various filters and filtercomponents. Density functional theory (DFT) was able to provide isobaric heat capacities for Al–Fe and Al–Fe-Si systems that outclassed the empirical Neumann–Kopp rule and matched the experimental values over a wide temperature range. Moreover, DFT calculations clarified that the formation of hercynite at the interface between alumina filters and steel melt was the result of a solid-state reaction involving high concentrations of FeO. Ex-situ Raman spectroscopy was used to compare carbon-bonded alumina filters using different bindersfrom Carbores®P to environmentally friendly lactose/tannin, as a function of heat treatment. For these carbon-bonded filters, the prominent D and G bands were used to confirm the existence of graphitization processes and determine the size of graphite clusters resulting from these processes. In order to investigate the pyrolysis processes occurring in selected binder constituents of the lactose/tannin filters, the evolution of Raman spectra with temperature was analyzed via in-situ measurements. Wherever it was appropriate, experimental Raman data were compared with DFT-simulated spectra. Further, Raman spectroscopy was used to study the thermally induced formation of metastable alumina, helping to understand the structural changes that take place during the transformation of boehmite (γ-AlO(OH)) to corundum (α-Al2O3) via metastable transition phases: γ-Al2O3, δ-Al2O3, and θ-Al2O3.

show abstract

Dilute magnetism and vibrational entropy inFe2Al5

Cited by 17 publications

References 37 publications

Mössbauer spectroscopic and XRD studies of two η-Fe2Al5 intermetallics

Mössbauer spectroscopic and XRD studies of two η-Fe2Al5 intermetallics

Structure and stability of Al2Fe and Al5Fe2: First-principles total energy and phonon calculations

Structural and Thermodynamic Properties of Filter Materials: A Raman and DFT Investigation

Contact Info

Product

Resources

About