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1. Medium‐Entropy Engineering of Magnetism in Layered Antiferromagnet Cu _x Ni _{2(1‐ x )} Cr _x P ₂ S ₆

   https://doi.org/10.1002/adfm.202418722  

   Upreti, Dinesh; Basnet, Rabindra; Sharma, M M; Chhetri, Santosh Karki; Acharya, Gokul; Nabi, Md_Rafique Un; Sakon, Josh; Benamara, Mourad; Mortazavi, Mansour; Hu, Jin (December 2024, Advanced Functional Materials)

   Abstract Antiferromagnetic van der Waals‐typeM₂P₂X₆compounds provide a versatile material platform for studying 2D magnetism and relevant phenomena. Establishing ferromagnetism in 2D materials is technologically valuable. Though magnetism is generally tunable via a chemical way, it is challenging to induce ferromagnetism with isovalent chalcogen and bimetallic substitutions inM₂P₂X₆. Here, we report co‐substitution of Cu¹⁺and Cr³⁺for Ni²⁺in Ni₂P₂S₆, creating Cu_xNi_2(1‐x)Cr_xP₂S₆medium‐entropy alloys spanning a full substitution range (x= 0 to 1). Such substitution strategy leads to a unique evolution in crystal structure and magnetic phases that are distinct from traditional isovalent bimetallic doping, with Cu and Cr co‐substitution enhancing ferromagnetic correlations and generating a weak ferromagnetic phase in intermediate compositions. This aliovalent substitution strategy offers a universal approach for tuning layered magnetism in antiferromagnetic systems, which along with the potential for light‐matter interaction and high‐temperature ferroelectricity, can enable multifunctional device applications. 

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2. Reinvestigation of the ν ₃ – ν ₆ Coriolis interaction in trifluoroiodomethane

   https://doi.org/10.1039/D4CP02640C  

   Bhujel, Arun; Akter, Salma; Ali, Muhammad Qasim; Park, G Barratt (November 2024, Physical Chemistry Chemical Physics)

   An updated fit to the interacting levelsν₃andν₆of CF₃I has been evaluated in this work. 

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3. Sr(Ag _1−x Li _x ) ₂ Se ₂ and [Sr ₃ Se ₂ ][(Ag _1−x Li _x ) ₂ Se ₂ ] Tunable Direct Band Gap Semiconductors

   https://doi.org/10.1002/anie.202301191  

   Zhou, Xiuquan; Wilfong, Brandon; Chen, Xinglong; Laing, Craig; Pandey, Indra R.; Chen, Ying‐Pin; Chen, Yu‐Sheng; Chung, Duck‐Young; Kanatzidis, Mercouri G. (March 2023, Angewandte Chemie International Edition)

   Abstract Synthesizing solids in molten fluxes enables the rapid diffusion of soluble species at temperatures lower than in solid‐state reactions, leading to crystal formation of kinetically stable compounds. In this study, we demonstrate the effectiveness of mixed hydroxide and halide fluxes in synthesizing complex Sr/Ag/Se in mixed LiOH/LiCl. We have accessed a series of two‐dimensional Sr(Ag_1−xLi_x)₂Se₂layered phases. With increased LiOH/LiCl ratio or reaction temperature, Li partially substituted Ag to form solid solutions of Sr(Ag_1−xLi_x)₂Se₂withxup to 0.45. In addition, a new type of intergrowth compound [Sr₃Se₂][(Ag_1−xLi_x)₂Se₂] was synthesized upon further reaction of Sr(Ag_1−xLi_x)₂Se₂with SrSe. Both Sr(Ag_1−xLi_x)₂Se₂and [Sr₃Se₂][(Ag_1−xLi_x)₂Se₂] exhibit a direct band gap, which increases with increasing Li substitution (x). Therefore, the band gap of Sr(Ag_1−xLi_x)₂Se₂can be precisely tuned via fine‐tuningxthat is controlled by only the flux ratio and temperature. 

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4. Bandgap engineering in quasi-1D Zr _1−x Ti _x S ₃ (0 ≤ x ≤ 1) solid solutions

   https://doi.org/10.1039/d5tc02480c  

   Muratov, Dmitry S; Bianco, Ettore; Karpenkov, Dmitry; Castellero, Alberto; Lipatov, Alexey; Maurino, Valter; Sinitskii, Alexander (January 2025, Journal of Materials Chemistry C)

   We synthesized a series of Zr_1−xTi_xS₃solid solutions (0 ≤x≤ 1)viaa direct reaction between Zr–Ti alloys and sulfur vapor at 600 °C. These solid solutions have a tunable bandgap in the 1–2 eV range that linearly increases with the Zr content. 

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5. Superconductivity and Pronounced Electron‐Phonon Coupling in Rock‐Salt Al _1−x O _1−x and Ti _1−x O _1−x

   https://doi.org/10.1002/aelm.202400141  

   Žguns, Pjotrs; Gedik, Nuh; Yildiz, Bilge; Li, Ju (May 2024, Advanced Electronic Materials)

   Abstract The highest ambient‐pressure Tc among binary compounds is 40 K (MgB2). Higher Tc is achieved in high‐pressure hydrides or multielement cuprates. Alternatively, are explored superconducting properties of binary, metastable sub‐oxides, that may emerge under extremely low oxygen partial pressure. The emphasis is on the rock‐salt structure, which is known to promote superconductivity, and exploring AlO, ScO, TiO, and NbO. Dynamic lattice stability is achieved by introducing metal and oxygen vacancies in the fashion of Nb_1−xO_1−x‐type structure (x = ¼). The electron‐phonon (e‐ph) coupling is remarkably large in Al_1−xO_1−xand Ti_1−xO_1−x(λ ≈ 2 at x = ¼), with Tc ≈ 35 K according to the Allen–Dynes equation. Significantly, the coupling strength is comparable to that in high‐pressure hydrides, yet, in contrast to hydrides and MgB2, the coupling is largely driven by low frequency phonons. Sc_1−xO_1−xand Nb_1−xO_1−xshow significantly smaller λ and Tc. Further, hydrogen intercalation to boost λ and Tc is investigated. Only Ti_1−x(O_1−xHx) and Nb_1−x(O_1−xHx) are dynamically stable upon intercalation, where H, respectively, decreases and increases Tc. The effect of H doping on electronic structure and Tc is discussed. Altogether, the study suggests that metal sub‐oxides are promising compounds to achieve strong e‐ph coupling at ambient pressure. 

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