Increasing both the energy barrier for magnetization reversal and the coercive field of the hysteresis loop are significant challenges in the field of single-molecule magnets (SMMs). Coordination geometries of lanthanide ions and magnetic interactions between lanthanide ions are both important for guiding the magnetic behavior of SMMs. We report a high energy barrier of 657 K (457 cm ) in a diamagnetic-ion-diluted lanthanide chain compound with a constrained bisphenoid symmetry (D ); this energy barrier is substantially higher than the barrier of 567 K (394 cm ) of the non-diluted chain compound with intrachain ferromagnetic interactions. Although intrachain magnetic interaction lowers the energy barrier for magnetization reversal, it can greatly enhance the coercive fields and zero-field remanence of the hysteresis loops, which is crucial for the rational design of high-performance SMMs. Factors related to the coordination sphere of the lanthanide center, which govern the high magnetic relaxation barriers through the second excited Kramer's doublets and the magnetic interactions that affect the hysteresis loops, were revealed through ab initio calculations.
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http://dx.doi.org/10.1002/chem.201705350 | DOI Listing |
Chem Commun (Camb)
January 2025
Key Laboratory of Functional Membrane Material and Membrane Technology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 189 Songling Road, Qingdao, 266101, China.
In traditional binary heterojunction catalysts, mismatched energy band structures lead to higher electron transfer barriers. By reducing the work function difference a ternary Ru-RuS/MoS heterostructure, we developed a HER catalyst with remarkable activity (17 mV@10 mA cm) and excellent stability (300 h@500 mA cm).
View Article and Find Full Text PDFPhys Chem Chem Phys
January 2025
Institute of Chemistry, Department of Fundamental Chemistry, University of São Paulo, Av. Prof. Lineu Prestes, 748 - Butantã, São Paulo, 05508-900, Brazil.
The conformational isomerization of nitrous acid (HONO) promoted by excitation of the or stretching normal coordinates is the first observed case of an infrared-induced photochemical reaction. The energy captured by the excited normal modes is redistributed into a highly excited vibrational level of the torsion normal coordinate, which is the isomerization reaction coordinate. Herein, we present simple numerical methods to qualitatively investigate the coupling between the normal coordinates and the possible gateways for vibrational energy redistribution leading to the isomerization process.
View Article and Find Full Text PDFChem Sci
January 2025
Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University Suzhou Jiangsu 215123 China
Understanding the oxygen reduction reaction (ORR) mechanism and accurately characterizing the reaction interface are essential for improving fuel cell efficiency. We developed an active learning framework combining machine learning force fields and enhanced sampling to explore the dynamics and kinetics of the ORR on Fe-N/C using a fully explicit solvent model. Different possible reaction paths have been explored and the O adsorption process is confirmed as the rate-determining step of the ORR at the Fe-N/C-water interface, which needs to overcome a free energy barrier of 0.
View Article and Find Full Text PDFHeliyon
January 2025
Department of Physics, Facility of Science, King Abdulaziz University, Jeddah, Saudi Arabia.
The influence of variations in indium concentration and temperature on threshold current density (J) in In Ga As/GaAs ( = 0, 0.8 and 0.16) quantum dot (QD) laser diodes - synthesized via molecular beam epitaxy (MBE) with three distinct indium concentrations on GaAs (001) substrates - was meticulously examined.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Beihang University, 37 Xue Yuan Road, Hai Dian District, 100191, Beijing, CHINA.
Sodium-ion batteries (SIBs), endowed with relatively small Stokes radius and low desolvation energy for Na+, are reckoned as a promising candidate for fast-charging endeavors. However, the C-rate charging capability of practical energy-dense sodium-ion pouch cells is currently limited to ≤1C, due to the high propensity for detrimental metallic Na plating on the hard carbon (HC) anode at elevated rates. Here, an ampere-hour-level sodium-ion pouch cell capable of 3C charging is successfully developed via phosphorus (P)-sulfur (S) interphase chemistry.
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