Magnetism of Invar alloys under pressure examined by inelastic x-ray scattering

Rueff, Jean‐Pascal; Shukla, Abhay; Kaprolat, A.; Krisch, M.; Lorenzen, M.; Sette, F.; Verbeni, R.

doi:10.1103/physrevb.63.132409

Cited by 66 publications

(77 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These critical pressures correspond to the values of the magnetic phase transition from the LS to the nonmagnetic state obtained by inelastic x-ray scattering. 50 As a consequence, it seems that in addition to the fact that the treated Fe-Ni Invar alloy become harder to squeeze under pressure, we need to add the feature that owing to the important magnetoelastic coupling in these materials, when they are mechanically stressed below T C , these systems increase notoriously their Curie temperature, leading to an enhancement of the Invar properties, where an almost zero thermal expansion is observed. Up to now the usual way to attempt to increase T C in this FeNi system is through increasing the Ni content, however, in doing so the magnetovolume effects lose importance because Ni atoms stabilize much more the HS state.…”

Section: Resultsmentioning

confidence: 99%

Stress-induced large Curie temperature enhancement inFe64Ni36Invar alloy

et al. 2009

View full text Add to dashboard Cite

We have succeeded in increasing up to 150 K the Curie temperature in the Fe 64 Ni 36 invar alloy by means of a severe mechanical treatment followed by a heating up to 1073 K. The invar behavior is still present as revealed by the combination of magnetic measurements with neutron and x-ray techniques under extreme conditions, such as high temperature and high pressure. The proposed explanation is based in a selective induced microstrain around the Fe atoms, which causes a slight increase in the Fe-Fe interatomic distances, thus reinforcing ferromagnetic interactions due to the strong magnetoelastic coupling in these invar compounds.

show abstract

Section: Resultsmentioning

confidence: 99%

Stress-induced large Curie temperature enhancement inFe64Ni36Invar alloy

et al. 2009

View full text Add to dashboard Cite

show abstract

“…Both lineshapes are found to be identical, and the relative intensity of the Kβ' satellite around 86-eV seems consistent with a high-spin state. 32 …”

Section: Ambient Pressurementioning

confidence: 99%

Charge transfer in FeOCl intercalation compounds and its pressure dependence: An x-ray spectroscopic study

et al. 2010

View full text Add to dashboard Cite

We present a study of charge transfer in Na-intercalated FeOCl and polyaniline-intercalated FeOCl using high-resolution x-ray absorption spectroscopy and resonant x-ray emission spectroscopy at the Fe-K edge. By comparing the experimental data with ab-initio simulations, we are able to unambiguously distinguish the spectral changes which appear due to intercalation into those of electronic origin and those of structural origin. For both systems, we find that about 25% of the Fe sites are reduced to Fe 2+ via charge transfer between FeOCl and the intercalate. This is about twice as large as the Fe 2+ fraction reported in studies using Mössbauer spectroscopy. This discrepancy is ascribed to the fact that the charge transfer occurs on the same time scale as the Mössbauer effect itself. Our result suggests that every intercalated atom or molecule is involved in the chargetransfer process, thus making this process a prerequisite for intercalation. The Fe 2+ fraction is found to increase with pressure for polyaniline-FeOCl, hinting at an enhancement of the conductivity in the FeOCl intercalation compounds under pressure.

show abstract

“…A further typical assumption at the line shape analysis is that the fluorescence yield is not affected by the transition, so the XES intensity at a fluorescence feature is identical for both states; however, it is known that the Kβ : Kα intensity ratio can show some chemical dependence [41]. Since the IAD approach is used more and more widely [18,42,43,44,45,46], it is important to test the validity of these assumptions.…”

Section: Time-resolved Xes: Validation Of the Methodology For Line Shmentioning

confidence: 99%

Spin-state studies with XES and RIXS: From static to ultrafast

Vankó

Bordage

Glatzel

et al. 2013

Journal of Electron Spectroscopy and Related Phenomena

View full text Add to dashboard Cite

We report on extending hard X-ray emission spectroscopy (XES) together with resonant inelastic X-ray scattering (RIXS) to study ultrafast phenomena in a pump-probe scheme at MHz repetition rates. The investigated system consists of low-spin (LS) Fe II complex compounds, where optical pulses induce a spinstate transition to their ≈ nanosecond-lived high-spin (HS) state. Time-resolved XES clearly reflects the spinstate variations with very high signal-to-noise ratio, in agreement with HS-LS difference spectra measured via thermally induced spin crossover, and reference HS-LS systems in static experiments. 1s2p RIXS, measured at the Fe 1s pre-edge region shows variations after laser excitation, which are consistent with the formation of the HS state. Our results demonstrate that now X-ray spectroscopy experiments with overall rather weak signals, such as RIXS, can be reliably exploited to study chemical and physical transformations on ultrafast time scales.

show abstract

Magnetism of Invar alloys under pressure examined by inelastic x-ray scattering

Cited by 66 publications

References 17 publications

Stress-induced large Curie temperature enhancement inFe64Ni36Invar alloy

Stress-induced large Curie temperature enhancement inFe64Ni36Invar alloy

Charge transfer in FeOCl intercalation compounds and its pressure dependence: An x-ray spectroscopic study

Spin-state studies with XES and RIXS: From static to ultrafast

Contact Info

Product

Resources

About