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1. Sputtered L 1 0 ‐FePd and its Synthetic Antiferromagnet on Si/SiO 2 Wafers for Scalable Spintronics

   https://doi.org/10.1002/adfm.202214201  

   Lyu, Deyuan ; Shoup, Jenae E. ; Huang, Dingbin ; García‐Barriocanal, Javier ; Jia, Qi ; Echtenkamp, William ; Rojas, Geoffrey A. ; Yu, Guichuan ; Zink, Brandon R. ; Wang, Xiaojia ; et al ( February 2023 , Advanced Functional Materials)

   As a promising alternative to the mainstream CoFeB/MgO system with interfacial perpendicular magnetic anisotropy (PMA),L1₀‐FePd and its synthetic antiferromagnet (SAF) structure with large crystalline PMA can support spintronic devices with sufficient thermal stability at sub‐5 nm sizes. However, the compatibility requirement of preparingL1₀‐FePd thin films on Si/SiO₂wafers is still unmet. In this paper, high‐qualityL1₀‐FePd and its SAF on Si/SiO₂wafers are prepared by coating the amorphous SiO₂surface with an MgO(001) seed layer. The preparedL1₀‐FePd single layer and SAF stack are highly (001)‐textured, showing strong PMA, low damping, and sizeable interlayer exchange coupling, respectively. Systematic characterizations, including advanced X‐ray diffraction measurement and atomic resolution‐scanning transmission electron microscopy, are conducted to explain the outstanding performance ofL1₀‐FePd layers. A fully‐epitaxial growth that starts from MgO seed layer, induces the (001) texture ofL1₀‐FePd, and extends through the SAF spacer is observed. This study makes the vision of scalable spintronics more practical.

    

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2. Isoelectronic perturbations to f - d -electron hybridization and the enhancement of hidden order in URu 2 Si 2

   https://doi.org/10.1073/pnas.2026591118  

   Wolowiec, Christian T. ; Kanchanavatee, Noravee ; Huang, Kevin ; Ran, Sheng ; Breindel, Alexander J. ; Pouse, Naveen ; Sasmal, Kalyan ; Baumbach, Ryan E. ; Chappell, Greta ; Riseborough, Peter S. ; et al ( May 2021 , Proceedings of the National Academy of Sciences)

   Electrical resistivity measurements were performed on single crystals of URu_2–xOs_xSi₂up tox= 0.28 under hydrostatic pressure up toP= 2 GPa. As the Os concentration,x, is increased, 1) the lattice expands, creating an effective negative chemical pressureP_ch(x); 2) the hidden-order (HO) phase is enhanced and the system is driven toward a large-moment antiferromagnetic (LMAFM) phase; and 3) less external pressureP_cis required to induce the HO→LMAFM phase transition. We compare the behavior of theT(x,P) phase boundary reported here for the URu_2-xOs_xSi₂system with previous reports of enhanced HO in URu₂Si₂upon tuning withPor similarly in URu_2–xFe_xSi₂upon tuning with positiveP_ch(x). It is noteworthy that pressure, Fe substitution, and Os substitution are the only known perturbations that enhance the HO phase and induce the first-order transition to the LMAFM phase in URu₂Si₂. We present a scenario in which the application of pressure or the isoelectronic substitution of Fe and Os ions for Ru results in an increase in the hybridization of the U-5f-electron and transition metald-electron states which leads to electronic instability in the paramagnetic phase and the concurrent formation of HO (and LMAFM) in URu₂Si₂. Calculations in the tight-binding approximation are included to determine the strength of hybridization between the U-5f-electron states and thed-electron states of Ru and its isoelectronic Fe and Os substituents in URu₂Si₂.

    

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3. Crystal and Electronic Structure and Optical Properties of AE 2 SiP 4 ( AE = Sr, Eu, Ba) and Ba 4 Si 3 P 8

   https://doi.org/10.1002/zaac.201800430  

   Mark, Justin ; Dolyniuk, Juli‐Anna ; Tran, Nhon ; Kovnir, Kirill ( November 2018 , Zeitschrift für anorganische und allgemeine Chemie)

   Three new compounds in theAE‐Si‐P (AE= Sr, Eu, Ba) systems are reported. Sr₂SiP₄and Eu₂SiP₄, the first members of their respective ternary systems, are isostructural to previously reported Ba₂SiP₄and crystallize in the noncentrosymmetricI42d(no. 122) space group. Ba₄Si₃P₈crystallizes in the new structure type, inP2₁/c(no. 14) space group,mP‐120 Pearson symbol, Wyckoff sequencee³⁰. In the crystal structures of Sr₂SiP₄and Eu₂SiP₄all SiP₄tetrahedral building blocks are connected via formation of P–P bonds forming a three‐dimensional framework. In the crystal structure of Ba₄Si₃P₈, Si‐P tetrahedral chains formed by corner‐sharing, edge‐sharing, and P–P bonds are surrounded by Ba cations. This results in a quasi‐one‐dimensional structure. Electronic structure calculations and UV/Vis measurements suggest that theAE₂SiP₄(AE= Sr, Eu, Ba) are direct bandgap semiconductors with bandgaps of ca. 1.4 eV and have potential for thermoelectric applications.

    

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4. Phase Stabilized MOCVD Growth of β‐Ga 2 O 3 Using SiO x on c‐Plane Sapphire and AlN/Sapphire Template

   https://doi.org/10.1002/pssa.202300036  

   Jewel, Mohi Uddin ; Hasan, Samiul ; Crittenden, Scott R. ; Avrutin, Vitaliy ; Özgür, Ümit ; Morkoç, Hadis ; Ahmad, Iftikhar ( April 2023 , physica status solidi (a))

   The growth of monoclinic phase‐pure gallium oxide (β‐Ga₂O₃) layers by metal–organic chemical vapor deposition on c‐plane sapphire and aluminum nitride (AlN) templates using silicon‐oxygen bonding (SiO_x) as a phase stabilizer is reported. The β‐Ga₂O₃layers are grown using triethylgallium, oxygen, and silane for gallium, oxygen, and silicon precursors, respectively, at 700 °C, with and without silane flow in the process. The samples grown on sapphire with SiO_xphase stabilization show a notable change from samples without phase stabilization in the roughness and resistivity, from 16.2 to 4.2 nm and from 85.82 to 135.64 Ω cm, respectively. X‐ray diffraction reveals a pure‐monoclinic phase, and Raman spatial mapping exhibits higher tensile strain in the films in the presence of SiO_x. The β‐Ga₂O₃layers grown on an AlN template, using the same processes as for sapphire, show an excellent epitaxial relationship between β‐Ga₂O₃and AlN and have a significant change in β‐Ga₂O₃surface morphology.

    

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5. Structural dynamics of PtSn/SiO 2 for propane dehydrogenation

   https://doi.org/10.1039/D4CY00725E  

   Yu, Kewei ; Scarpelli, Matthew ; Sourav, Sagar ; Worrad, Alfred ; Boscoboinik, J Anibal ; Ma, Lu ; Ehrlich, Steven N ; Marinkovic, Nebojsa ; Zheng, Weiqing ; Vlachos, Dionisios G ( August 2024 , Catalysis Science & Technology)

   Operandocharacterization reveals the structural dynamics of PtSn/SiO₂catalysts, hinting at a Pt-rich surface configuration for optimal propane dehydrogenation performance.

    

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