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1. Tetragonal Kondo Insulator EuCd ₂ Sb ₂ Discovered via High Pressure High Temperature Synthesis

   https://doi.org/10.1002/adfm.202303612  

   Jimenez, Jose L.; Melnick, Corey; Koirala, Krishna Prasad; Adler, Ran; Wang, Fei; Berrada, Meryem; Chen, Bin; Wang, Le; Walker, David; Kotliar, Gabriel; et al (July 2023, Advanced Functional Materials)

   Abstract Magnetic and electronic properties of quantum materials heavily rely on the crystal structure even in the same chemical compositions. In this study, it is demonstrated that a layered tetragonal EuCd 2 Sb 2 structure can be obtained by treating bulk trigonal EuCd 2 Sb 2 under high pressure (6 GPa) and high temperature (600 °C). Magnetization measurements of the newly formed layered tetragonal EuCd 2 Sb 2 confirm an antiferromagnetic ordering with Neel temperature ( T N ) around 16 K, which is significantly higher than that ( T N ≈ 7 K) of trigonal EuCd 2 Sb 2 , consistent with heat capacity measurements. Moreover, bad metal behavior is observed in the temperature dependence of the electrical resistivity and the resistivity shows a dramatic increase around the Neel temperature. Electronic structure calculations with local density approximation dynamic mean–field theory (LDA+DMFT) show that this material is strongly correlated with well‐formed large magnetic moments, due to Hund's coupling, which is known to dramatically suppress the Kondo scale. 

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2. High-Performance WS ₂ MOSFETs with Bilayer WS ₂ Contacts

   https://doi.org/10.1021/acsomega.4c04431  

   Jin, Lun; Wen, Jiaxuan; Odlyzko, Michael; Seaton, Nicholas; Li, Ruixue; Haratipour, Nazila; Koester, Steven_J (July 2024, ACS Omega)
3. Stability of the Y ₂ O ₃ –SiO ₂ system in high‐temperature, high‐velocity water vapor

   https://doi.org/10.1111/jace.16915  

   Parker, Cory G; Opila, Elizabeth J (April 2020, Journal of the American Ceramic Society)

   Abstract High‐temperature, high‐velocity water vapor (steam‐jet) exposures were conducted on Y₂O₃, Y₂SiO₅, Y₂Si₂O₇, and SiO₂for 60 hours at 1400°C. Volatility of Y₂O₃was not observed. Phase‐pure Y₂SiO₅exhibited SiO₂loss forming Y₂O₃and porosity. A mixed porous and dense Y₂SiO₅layer formed on the surface of Y₂Si₂O₇due to SiO₂depletion. The mechanisms and kinetics of the reaction between SiO₂and H₂O(g) to form Si(OH)₄(g) from Y₂SiO₅, Y₂Si₂O₇, and SiO₂are discussed. 

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4. A Novel High‐Pressure Tin Oxynitride Sn ₂ N ₂ O

   https://doi.org/10.1002/chem.201904529  

   Bhat, Shrikant; Wiehl, Leonore; Haseen, Shariq; Kroll, Peter; Glazyrin, Konstantin; Gollé‐Leidreiter, Philipp; Kolb, Ute; Farla, Robert; Tseng, Jo‐Chi; Ionescu, Emanuel; et al (January 2020, Chemistry – A European Journal)
5. Structure-controlled graphene electrocatalysts for high-performance H ₂ O ₂ production

   https://doi.org/10.1039/d2ee00548d  

   Lee, Kyungbin; Lim, Jeonghoon; Lee, Michael J.; Ryu, Kun; Lee, Hoyoung; Kim, Jin Young; Ju, Hyunchul; Cho, Hyun-Seok; Kim, Byung-Hyun; Hatzell, Marta C.; et al (July 2022, Energy & Environmental Science)

   Metal-free carbon materials have emerged as cost-effective and high-performance catalysts for the production of hydrogen peroxide (H 2 O 2 ) through the two-electron oxygen reduction reaction (ORR). Here, we show that 3D crumpled graphene with controlled oxygen and defect configurations significantly improves the electrocatalytic production of H 2 O 2 . The crumpled graphene electrocatalyst with optimal defect structures and oxygen functional groups exhibits outstanding H 2 O 2 selectivity of 92–100% in a wide potential window of 0.05–0.7 V vs. reversible hydrogen electrode (RHE) and a high mass activity of 158 A g −1 at 0.65 V vs. RHE in alkaline media. In addition, the crumpled graphene catalyst showed an excellent H 2 O 2 production rate of 473.9 mmol gcat −1 h −1 and stability over 46 h at 0.4 V vs. RHE. Moreover, density functional theory calculations revealed the role of the functional groups and defect sites in the two-electron ORR pathway through the scaling relation between OOH and O adsorption strengths. These results establish a structure-mechanism-performance relationship of functionalized carbon catalysts for the effective production of H 2 O 2 . 

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