Publisher’s Note: Bulk sensitive x-ray absorption spectroscopy free of self-absorption effects [Phys. Rev. B<b>83</b>, 081106(R) (2011)]

Achkar, Andrew; Regier, T. Z.; Wadati, H.; Kim, Y.-J.; Zhang, H.; Hawthorn, D. G.

doi:10.1103/physrevb.83.129901

Cited by 52 publications

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“…All the spectra have been normalized to the beam flux measured by the upstream gold mesh. Total florescence yield signals are also collected but suffer serious spectral distortions due to self-absorption effect, especially for Mn-L edges [25].…”

Section: Soft X-ray Absorption Spectroscopy (Sxas)mentioning

confidence: 99%

Revealing and suppressing surface Mn(II) formation of Na0.44MnO2 electrodes for Na-ion batteries

et al. 2015

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Understanding and controlling the surface activities of electrode materials is critical for optimizing the battery performance, especially for nanoparticles with high surface area. Na 0.44 MnO 2 is a promising positive electrode material for large-scale sodium-ion batteries. However, its application in grid-scale energy storage requires improvements in cycling stability at high rate. Here, we performed comprehensive surface-sensitive soft x-ray spectroscopic studies of the Na 0.44 MnO 2 electrode. We are able to quantitatively determine the Mn evolution upon the potentials and cycle numbers. We reveal the Mn 2 + formation on the top 10 nm of Na 0.44 MnO 2 particles when the electrochemical potential is below 2.6 V, which does not occur in the bulk. A portion of the surface Mn 2+ compounds become electrochemically inactive after extended cycles, contributing to the capacity fading. Based on the spectroscopic discoveries, we demonstrate that cycling Na 0.44 MnO 2 above 3 V could efficiently suppress the Mn 2 + formation.Please cite this article as: R. Qiao, et al., Revealing and suppressing surface Mn(II) formation of Na 0.44 MnO 2 electrodes for Na-ion batteries, Nano Energy (2015), http://dx.

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Section: Soft X-ray Absorption Spectroscopy (Sxas)mentioning

confidence: 99%

Revealing and suppressing surface Mn(II) formation of Na0.44MnO2 electrodes for Na-ion batteries

et al. 2015

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“…Despite its bulk-sensitivity, the relationship between FY and the absorption coefficient is non-trivial and saturation effects become important in the TFY. 26,27 The saturation effects in the TFY often change the ratio of XMCD at the L 2 and L 3 edges and preclude applying the sum rule analysis to them.FePt thin films have drawn intense research interest owing to their potential for high density recording applications by using their magnetism. [28][29][30][31][32] FePt has a high uniaxial magnetic anisotropy when the L1 0 ordered structure is formed, and exhibits perpendicular magnetization in L1 0 -FePt (001) thin films, which makes it a canarXiv:1701.03156v2 [physics.ins-det]…”

mentioning

confidence: 99%

Capturing ultrafast magnetic dynamics by time-resolved soft x-ray magnetic circular dichroism

Takubo

Yamamoto

Hikita

et al. 2017

Applied Physics Letters

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Experiments of time-resolved x-ray magnetic circular dichroism (Tr-XMCD) and resonant x-ray scattering at a beamline BL07LSU in SPring-8 with a time-resolution of under 50 ps are presented. A micro-channel plate is utilized for the Tr-XMCD measurements at nearly normal incidence both in the partial electron and total fluorescence yield (PEY and TFY) modes at the L 2,3 absorption edges of the 3d transition-metals in the soft x-ray region. The ultrafast photo-induced demagnetization within 50 ps is observed on the dynamics of a magnetic material of FePt thin film, having a distinct threshold of the photon density. The spectrum in the PEY mode is less-distorted both at the L 2,3 edges compared with that in the TFY mode and has the potential to apply the sum rule analysis for XMCD spectra in pump-probed experiments.Control of electron, magnetic, and lattice states by optical excitations in magnetically ordered materials has attracted considerable attention due to their potential applications in electronic and magnetic recording media functioning on an ultrafast time scale below nanosecond (ns, 10 −9 second, GHz range), since the observation of the ultrafast demagnetization in Ni within 1 picosecond (ps). 1 The ultrafast photo-induced changes of magnetic states are non-equilibrium phenomena and several mechanisms have been proposed to understand them. 2-4 These phenomena generally involve fast structural changes near surface region 5,6 and therefore require cooperative effects, inevitably having a threshold of the photon density.To capture their non-equilibrium dynamics, ultrafast time-resolved experiments have been carried out using ultra-short laser pulses. 3 Recently, the development of a bunched synchrotron light source, 7-11 and x-ray free electron lasers 12-14 have enabled investigation of the dynamic phenomena with element selectivity by tuning the photon energy of the x-ray to the absorption edges of the constituent elements. Especially, time-resolved soft x-ray spectroscopy has many unique characteristics, such as element specificity, chemical specificity and surface sensitivity, which make them versatile for application in a wide range of scientific fields including spintronics and environmental science. Owing to its importance, various time-resolved soft x-ray spectroscopy studies have been carried out. [15][16][17][18][19][20][21] The time-resolved x-ray magnetic circular dichroism (Tr-XMCD) and resonant soft x-ray scattering (Tr-RSXS) measurements for magnetic and electronic materials have been conducted in LCLS, 13,14 ALS, 9 and BESSY II slicing facilities. 10,11,[15][16][17][18][19] The timeresolved x-ray magneto optical Kerr effect (XMOKE) measurements have also been conducted in FERMI. 12 Tr-XMCD measurements at the M absorption below hv <100 eV have also been performed by using high harmonics generation from tabletop lasers in recent years. 22 XMCD at the L 2,3 absorption of 3d transition-metals a) Electronic mail: ktakubo@issp.u-tokyo.ac.jp in the soft x-ray region (hv > 400 eV) is a powerful tool ...

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“…Their approach, however, assumes that the linear attenuation coefficient of the material under study is known, whereas measurements of linear absorption coefficients require in principle XAS spectra already free of self-absorption effects. Recently, Achkar et al [18,19] introduced the inverse partial fluorescence yield (IPFY) method which relies on measuring the x-ray emission fluorescence from an element or core-hole excitation that is different from the PRL 112, …”

mentioning

confidence: 99%

“…In conclusion, one can state that mitigation of self-absorption has been and still is a topic of active research (see, e.g., Refs. [18][19][20][21]). …”

mentioning

confidence: 99%

High Energy Resolution Off-Resonant Spectroscopy for X-Ray Absorption Spectra Free of Self-Absorption Effects

et al. 2014

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X-ray emission spectra recorded in the off-resonant regime carry information on the density of unoccupied states. It is known that by employing the Kramers-Heisenberg formalism, the high energy resolution off-resonant spectroscopy (HEROS) is equivalent to the x-ray absorption spectroscopy (XAS) technique and provides the same electronic state information. Moreover, in the present Letter we demonstrate that the shape of HEROS spectra is not modified by self-absorption effects. Therefore, in contrast to the fluorescence-based XAS techniques, the recorded shape of the spectra is independent of the sample concentration or thickness. The HEROS may thus be used as an experimental technique when precise information about specific absorption features and their strengths is crucial for chemical speciation or theoretical evaluation. DOI: 10.1103/PhysRevLett.112.173003 PACS numbers: 32.30.Rj, 31.15.ag, 32.70.Jz, 32.80.Fb The high-intensity and highly monochromatic x-ray radiation available at synchrotron sources allow researchers from different disciplines to study the local electronic and geometric structure of materials by means of x-ray absorption spectroscopy (XAS). To record a XAS spectrum the x-ray energy is tuned around the electron binding energy of the element of interest, thereby exciting electrons from one of the core levels to unoccupied states or into the continuum. The photo-absorption process depends on the photon energy and is a measure of the material's absorption coefficient which in turn provides information on the material properties. The energy region around the absorption edge, namely the x-ray absorption near edge structure (XANES), reflects the density of empty states [1]. The region starting about 100 eV above the absorption edge is called the extended x-ray absorption fine structure (EXAFS) region, and the analysis of this region yields information on the local geometric structure [2].X-ray absorption spectra can be measured in the transmission, fluorescence, and electron-yield mode [3,4]. In the transmission mode, the XAS spectra are measured by recording the intensity of the photon beam before and after the sample. The fluorescence mode involves the use of x-ray emission spectroscopy (XES) techniques allowing detection of the fluorescence yield as a function of the incident photon energy. The XAS spectrum can be obtained from either the total fluorescence yield (TFY) or the partial fluorescence yield (PFY) measurements. In TFY the fluorescence intensity is integrated over a broad emission energy range, while in the PFY it is integrated over a selected emission energy range. In particular, the fluorescence yield integrated over an energy band centered at a given fluorescence line and narrower than the natural linewidth of the latter is referred to as the high energy resolution XAS [5,6]. It provides more detailed information about absorption features and allows precise chemical speciation [7].The field of x-ray absorption spectroscopy is a very important tool in the fields of physics, chemist...

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Publisher’s Note: Bulk sensitive x-ray absorption spectroscopy free of self-absorption effects [Phys. Rev. B83, 081106(R) (2011)]

Cited by 52 publications

References 0 publications

Revealing and suppressing surface Mn(II) formation of Na0.44MnO2 electrodes for Na-ion batteries

Revealing and suppressing surface Mn(II) formation of Na0.44MnO2 electrodes for Na-ion batteries

Capturing ultrafast magnetic dynamics by time-resolved soft x-ray magnetic circular dichroism

High Energy Resolution Off-Resonant Spectroscopy for X-Ray Absorption Spectra Free of Self-Absorption Effects

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