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1. Conduction electron spin resonance in the α -Yb 1−x Fe x AlB 4 (0 ⩽ x ⩽ 0.50) and α -LuAlB 4 compounds

   https://doi.org/10.1088/0953-8984/27/25/255601  

   Holanda, L. M. ; Lesseux, G. G. ; Magnavita, E. T. ; Ribeiro, R. A. ; Nakatsuji, S. ; Kuga, K. ; Fisk, Z. ; Oseroff, S. B. ; Urbano, R. R. ; Rettori, C. ; et al ( June 2015 , Journal of Physics: Condensed Matter)
2. Density functional theory investigation of the interaction of water with α−Al2O3 and α−Fe2O3 (11̲02 ) surfaces: Implications for surface reactivity

   https://doi.org/10.1103/PhysRevB.83.125407  

   Aboud, Shela ; Wilcox, Jennifer ; Brown, Gordon E. ( March 2011 , Physical Review B)
3. Measurement of spin mixing conductance in Ni 81 Fe 19 / α -W and Ni 81 Fe 19 / β -W heterostructures via ferromagnetic resonance

   https://doi.org/10.1063/1.5099913  

   Cao, W. ; Liu, J. ; Zangiabadi, A. ; Barmak, K. ; Bailey, W. E. ( July 2019 , Journal of Applied Physics)
4. Elemental Abundances in M31: Individual and Coadded Spectroscopic [Fe/H] and [α/Fe] throughout the M31 Halo with SPLASH

   https://doi.org/10.3847/1538-4357/acd5d3  

   Wojno, J. Leigh ; Gilbert, Karoline M. ; Kirby, Evan N. ; Escala, Ivanna ; Guhathakurta, Puragra ; Beaton, Rachael L. ; Kalirai, Jason ; Chiba, Masashi ; Majewski, Steven R. ( June 2023 , The Astrophysical Journal)

   We present spectroscopic chemical abundances of red giant branch stars in Andromeda (M31), using medium-resolution (R∼ 6000) spectra obtained via the Spectroscopic and Photometric Landscape of Andromeda’s Stellar Halo survey. In addition to individual chemical abundances, we coadd low signal-to-noise ratio spectra of stars to obtain a high enough signal to measure average [Fe/H] and [α/Fe] abundances. We obtain individual and coadded measurements for [Fe/H] and [α/Fe] for M31 halo stars, covering a range of 9–180 kpc in projected radius from the center of M31. With these measurements, we greatly increase the number of outer halo (R_proj> 50 kpc) M31 stars with spectroscopic [Fe/H] and [α/Fe], adding abundance measurements for 45 individual stars and 33 coadds from a pool of an additional 174 stars. We measure the spectroscopic metallicity ([Fe/H]) gradient, finding a negative radial gradient of −0.0084 ± 0.0008 for all stars in the halo, consistent with gradient measurements obtained using photometric metallicities. Using the first measurements of [α/Fe] for M31 halo stars covering a large range of projected radii, we find a positive gradient (+0.0027 ± 0.0005) in [α/Fe] as a function of projected radius. We also explore the distribution in [Fe/H]–[α/Fe] space as a function of projected radius for both individual and coadded measurements in the smooth halo, and compare these measurements to those stars potentially associated with substructure. These spectroscopic abundance distributions add to existing evidence that M31 has had an appreciably different formation and merger history compared to our own Galaxy.

    

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5. Polaronic optical transitions in hematite (α-Fe 2 O 3 ) revealed by first-principles electron–phonon coupling

   https://doi.org/10.1063/5.0116233  

   Shelton, Jacob L. ; Knowles, Kathryn E. ( November 2022 , The Journal of Chemical Physics)

   Polaron formation following optical absorption is a key process that defines the photophysical properties of many semiconducting transition metal oxides, which comprise an important class of materials with potential optoelectronic and photocatalytic applications. In this work, we use hematite (α-Fe 2 O 3 ) as a model transition metal oxide semiconductor to demonstrate the feasibility of direct optical population of band edge polaronic states. We employ first-principles electron–phonon computations within the framework of the density functional theory+ U+ J method to reveal the presence of these states within a thermal distribution of phonon displacements and model their evolution with temperature. Our computations reproduce the temperature dependence of the optical dielectric function of hematite with remarkable accuracy and indicate that the band edge optical absorption and second-order resonance Raman spectra arise from polaronic optical transitions involving coupling to longitudinal optical phonons with energies greater than 50 meV. Additionally, we find that the resulting polaron comprises an electron localized to two adjacent Fe atoms with distortions that lie primarily along the coordinates of phonons with energies of 31 and 81 meV. 

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