# FS-PEX

 2019-06-1907:10 [PUBDB-2019-02497] Journal Article Upadhyay, C. Dielectric relaxations in $Ho_{2}Ti_{2}O_{7}$ and $Dy_{2}Ti_{2}O_{7}$ pyrochlores Journal of physics and chemistry of solids 134, 201 - 208 (2019) [10.1016/j.jpcs.2019.06.010]   Dielectric measurements of $Ho_{2}Ti_{2}O_{7}$ and $Dy_{2}Ti_{2}O_{7}$ cubic pyrochlore show two distinctly defined relaxations around 90K and 36K. The nature and possible origin of these relaxations have been determined. [...] Published on 2019-06-14. Available in OpenAccess from 2020-06-14.: PDF PDF (PDFA); Restricted: PDF PDF (PDFA); 2019-06-1713:56 [PUBDB-2019-02482] Journal Article et al Bond-stretching force constants and vibrational frequencies in ternary zinc-blende alloys: A systematic comparison of (In,Ga)P, (In,Ga)As and Zn(Se,Te) epl 126(3), 36002 (2019) [10.1209/0295-5075/126/36002]   We present element-specific effective bond-stretching force constants and Einstein frequencies of (In,Ga)P ternary alloys determined by temperature-dependent extended x-ray absorption fine structure spectroscopy. The bond-stretching force constants of both bond species show a nearly linear composition dependence between the values of GaP and InP. [...] Published on 2019-06-19. Available in OpenAccess from 2020-06-19.: PDF PDF (PDFA); Restricted: PDF PDF (PDFA); 2019-06-0414:06 [PUBDB-2019-02412] Journal Article et al Characterization of Native Oxide and Passive Film on Austenite/Ferrite Phases of Duplex Stainless Steel Using Synchrotron HAXPEEM Journal of the Electrochemical Society 166(11), C3336 - C3340 (2019) [10.1149/2.0421911jes]   A new measurement protocol was used for microscopic chemical analysis of surface oxide films with lateral resolution of 1 μm.The native air-formed oxide and an anodic passive film on austenite and ferrite phases of a 25Cr-7Ni super duplex stainless steelwere investigated using synchrotron hard X-ray photoemission electron microscopy (HAXPEEM). Pre-deposited Pt-markers, incombination with electron backscattering diffraction mapping (EBSD), allowed analysis of the native oxide on individual grains ofthe two phases and the passive film formed on the same area after electrochemical polarization of the sample. [...] OpenAccess: PDF PDF (PDFA); External link: Fulltext 2019-04-0910:50 [PUBDB-2019-01910] Preprint/Report et al Scientific Opportunities with an X-ray Free-Electron Laser Oscillator [arXiv:1903.09317]   An X-ray free-electron laser oscillator (XFELO) is a new type of hard X-ray source that would produce fully coherent pulses with meV bandwidth and stable intensity. The XFELO complements existing sources based on self-amplified spontaneous emission (SASE) from high-gain X-ray free-electron lasers (XFEL) that produce ultra-short pulses with broad-band chaotic spectra [...] OpenAccess: PDF PDF (PDFA); 2019-04-0812:46 [PUBDB-2019-01899] Journal Article et al Tunable Magnetic Phases at $\mathrm{Fe_{3}O_{4}/SrTiO_{3}}$ Oxide Interfaces ACS applied materials & interfaces 11(7), 7576 - 7583 (2019) [10.1021/acsami.8b20625]   We demonstrate the emergence and control of magnetic phases between magnetite (Fe$_3$O$_4$), a ferrimagnetic halfmetal, and SrTiO$_3$, a transparent nonmagnetic insulator considered the bedrock of oxide-based electronics. The Verwey transition (T$_V$) was detected to persist from bulk-like down to ultrathin Fe$_3$O$_4$ films, decreasing from 117 ± 4 K (38 nm) to 25 ± 4 K (2 nm), respectively. [...] Restricted: PDF PDF (PDFA); 2019-04-0315:00 [PUBDB-2019-01848] Journal Article/Contribution to a conference proceedings/Contribution to a book et al High-flux XAFS-beamline P64 at PETRA III Proceedings of the 13th International Conference on Synchrotron Radiation Instrumentation, SRI2018, TaipeiTaipei, Taiwan, 10 Jun 2018 - 15 Jun 2018 AIP conference proceedings 2054, 060031 (2019) [10.1063/1.5084662]   Beamline P64 at PETRA III is dedicated to x-ray absorption spectroscopy experiments which require high flux, like quick extended x-ray absorption fine structure spectroscopy on the sub-second time scale, high-resolution resonant emission spectroscopy, and x-ray absorption fine-structure spectroscopy of highly diluted systems. The beamline is installed at the high-energy storage ring PETRA III. [...] Published on 2019-01-16. Available in OpenAccess from 2020-01-16.: PDF PDF (PDFA); External link: Fulltext 2019-03-2909:19 [PUBDB-2019-01769] Journal Article et al Structure of tin phosphate glasses by neutron and X-ray diffraction   Neutron and X-ray diffraction experiments with large ranges of scattering vector, up to Q$_{max}$ of 400 nm$^{−1}$ and 250 nm$^{−1}$, respectively, were performed on (SnO)$_x$(P$_2$O5)$_{1-x}$ glasses with 0.5 ≤ x ≤ 0.7, and the structural parameters of the PO and SnO polyhedra were determined. The fraction of P–NBO (non-bridging oxygen) bonds increases systematically at the expense of the P–BO (bridging oxygen) bonds with SnO additions [...] OpenAccess: PDF PDF (PDFA); 2019-03-2614:39 [PUBDB-2019-01717] Journal Article et al Headgroup-ordered Monolayers of Uncharged Glycolipids Exhibit Selective Interactions with Ions The journal of physical chemistry letters 10, 1684 - 1690 (2019) [10.1021/acs.jpclett.8b03865]   Selective interactions of ions with charge-neutral saccharides can have far-reaching consequences in biological and wet-technological contexts but have so far been observed only indirectly. Here, we directly quantify by total-reflection x-ray fluorescence the preferential accumulation of ions near uncharged saccharide surfaces in the form of glycolipid Langmuir monolayers at air/water interfaces exhibiting different levels of structural ordering. [...] OpenAccess: PDF PDF (PDFA); 2019-03-1113:29 [PUBDB-2019-01443] Journal Article et al Origin of electronic localization in metal-insulator transition of phase change materials Applied physics reviews 113(26), 263502 (2018) [10.1063/1.5053574]   Tellurium based phase change materials are unique 3D-solids proposed to undergo Anderson type metal-insulator transition. However, the origin of this transition is not unambiguously understood. [...] Published on 2018-12-27. Available in OpenAccess from 2019-12-27.: PDF PDF (PDFA); 2019-03-1111:25 [PUBDB-2019-01434] Journal Article et al Role of antisite disorder, electron-electron correlations, and a surface valence transition in the electronic structure of $\mathrm{CeMnNi_{4}}$ Physical review / B 99(3), 035102 (2019) [10.1103/PhysRevB.99.035102]   $\mathrm{CeMnNi_{4}}$ exhibits an unusually large spin polarization, but its origin has baffled researchers for more than a decade. We use bulk sensitive hard x-ray photoelectron spectroscopy (HAXPES) and density functional theory based on the Green's function technique to demonstrate the importance of electron-electron correlations of both the Ni 3d (U$_{Ni}$) and Mn 3d (U$_{Mn}$) electrons in explaining the valence band of this multiply correlated material [...] OpenAccess: PDF PDF (PDFA);