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1. Thermodynamic assessment of BaO–Ln ₂ O ₃ (Ln = La, Pr, Eu, Gd, Er) systems

   https://doi.org/10.1111/jace.17060  

   Gong, Weiping; Liu, Yanzhi; Xie, Yun; Zhao, Zhenting; Ushakov, Sergey_V; Navrotsky, Alexandra (February 2020, Journal of the American Ceramic Society)

   Abstract Heat capacities and enthalpies of formation of BaGd₂O₄were determined by high‐temperature differential scanning calorimetry and high‐temperature oxide melt solution calorimetry, respectively. Thermodynamic stability of BaLn₂O₄compounds increases with decreasing Ln³⁺ionic radius. Previously reported data on BaNd₂O₄and BaSm₂O₄corroborate this trend. Missing data for compounds in BaO–Ln₂O₃(Ln = La, Pr, Eu, Er) systems were estimated from established relations, thermodynamic assessment was performed, and binary phase diagrams were calculated. 

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2. Synthesis and reduction of [(C ₅ H ₄ SiMe ₃ ) ₂ Ln(μ-OR)] ₂ (Ln = La, Ce) complexes: structural effects of bridging alkoxides

   https://doi.org/10.1039/D4DT02137A  

   Brown, Adrian N; Kelleher, Jack N; Brown, Alexander M; Saghy, Peter; Bohl, Joshua J; Robinson, Jerome R; Huh, Daniel N (January 2024, Dalton Transactions)

   Alcoholysis of (C₅H₄SiMe)₃Ln results in bimetallic complexes with unexpected decreases in Ln⋯Ln distances as bridging alkoxides become bulkier. These complexes were characterized by DOSY NMR, CV, DPV, and a La^IIspecies was observed by EPR. 

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3. Dynamics of Highly Active Ln ₃ IrO ₇ Catalysts for the Oxygen Evolution Reaction in Acid

   https://doi.org/10.1002/aenm.202402333  

   Edgington, Jane; Vicente, Rafael; Vispute, Sejal; Li, Ruihan; Sweers, Matthew_E; Sullivan, Simone_R; Fernandez, Pablo_S; Seitz, Linsey_C (August 2024, Advanced Energy Materials)

   Abstract An improved understanding of catalyst dynamics for the oxygen evolution reaction (OER) in acid is critical for informing the development of highly efficient, stable, and cost‐effective OER catalysts for proton exchange membrane water electrolysis applications. Herein highly tunable, active, and dynamic Ir 5+ materials are studied, Ln₃IrO₇(Ln = Pr, Nd, Sm, and Eu). Leveraging a combination of in situ and ex situ characterization, as well as an advanced mercury underpotential deposition technique for Ir surface site quantification, the dynamic nature of Ln₃IrO₇materials throughout electrochemical activation under OER conditions is characterized. The trends are elucidated between intrinsic OER activity, surface Ir site quantity, and metal site dissolution behavior as tuned by the Ln site's atomic number. A critical relationship is uncovered to show that maintenance of excellent OER activity throughout performance testing is correlated with a catalysts’ ability to preserve a high degree of Ir enrichment, where heightened stability of Ir sites interestingly parallels reduced stability of Ln sites throughout testing. It is found that as the Ln site's atomic number is decreased, the materials’ intrinsic OER performance improves, due to an increased thermodynamic driving force for Ln dissolution, which is hypothesized to enable the maintenance of highly active Ir‐based surface motifs. 

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4. Evaluating electrochemical accessibility of 4f ⁿ 5d ¹ and 4f ⁿ⁺¹ Ln( ii ) ions in (C ₅ H ₄ SiMe ₃ ) ₃ Ln and (C ₅ Me ₄ H) ₃ Ln complexes

   https://doi.org/10.1039/D1DT02427B  

   Trinh, Michael T.; Wedal, Justin C.; Evans, William J. (October 2021, Dalton Transactions)

   The reduction potentials (reported vs. Fc + /Fc) for a series of Cp′ 3 Ln complexes (Cp′ = C 5 H 4 SiMe 3 , Ln = lanthanide) were determined via electrochemistry in THF with [ n Bu 4 N][BPh 4 ] as the supporting electrolyte. The Ln( iii )/Ln( ii ) reduction potentials for Ln = Eu, Yb, Sm, and Tm (−1.07 to −2.83 V) follow the expected trend for stability of 4f 7 , 4f 14 , 4f 6 , and 4f 13 Ln( ii ) ions, respectively. The reduction potentials for Ln = Pr, Nd, Gd, Tb, Dy, Ho, Er, and Lu, that form 4f n 5d 1 Ln( ii ) ions ( n = 2–14), fall in a narrow range of −2.95 V to −3.14 V. Only cathodic events were observed for La and Ce at −3.36 V and −3.43 V, respectively. The reduction potentials of the Ln( ii ) compounds [K(2.2.2-cryptand)][Cp′ 3 Ln] (Ln = Pr, Sm, Eu) match those of the Cp′ 3 Ln complexes. The reduction potentials of nine (C 5 Me 4 H) 3 Ln complexes were also studied and found to be 0.05–0.24 V more negative than those of the Cp′ 3 Ln compounds. 

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5. Emergent Epitaxial Configuration of Pr ₃ IrO ₇ Domains via YSZ (111) Substrate

   https://doi.org/10.1002/sstr.202500005  

   Noh, Gahee; Guo, Lu; Pal, Pratap; Campbell, Neil; Rzchowski, Mark Steven; Eom, Chang‐Beom; Choi, Si‐Young (August 2025, Small Structures)

   The 5drare Earth iridate is an intriguing material with exhibiting exotic electronic and magnetic phases due to spin‐orbit coupled states. Ternary iridium oxidesLn₃IrO₇contain an unusual Ir⁵⁺(5d⁴) system, which remain a subject of active research. Fabricating epitaxialLn₃IrO₇films is challenging due to substrate compatibility, but it offers a valuable platform to explore electronic and magnetic behaviors under reduced dimensionality and substrate interactions, revealing novel phenomena based on Ir⁵⁺(5d⁴). In this regard, this demonstrates that Pr₃IrO₇with its highly anisotropic orthorhombic structure can be epitaxially grown on a cubic (111)‐oriented yttrium‐stabilized ZrO₂(YSZ) substrate. Pr₃IrO₇film exhibits six epitaxial domains, where the (220) and (202) planes aligning epitaxially to YSZ (111) with the threefold symmetry. This diverse domain configuration in Pr₃IrO₇film leads to unique magnetic properties, exhibiting spin‐glass‐like behavior. Pr₃IrO₇thin film offers a platform for exploring unconventional magnetic states, and their successful heteroepitaxy on YSZ substrates opens new avenues for discovering novel physical phenomena. 

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