Sharma Tanu, Tiwari Rupesh Kumar, Dey Sourav, Mariano Lorenzo A, Lunghi Alessandro, Rajaraman Gopalan
Department of Chemistry, Indian Institute of Technology Bombay Mumbai Maharashtra 400076 India
School of Physics and AMBER Research Centre, Trinity College Dublin 2 Ireland
Chem Sci. 2025 Jun 9. doi: 10.1039/d4sc07786e.
This study presents the investigation of spin-phonon coupling mechanisms in fullerene-based single-molecule magnets (SMMs) using CASSCF combined with DFT calculations. While lanthanide-based SMMs, particularly those with Dy ions, are known for their impressive blocking temperatures and relaxation barriers, endohedral metallofullerene (EMFs) offer a unique platform for housing low-coordinated lanthanides within rigid carbon cages. We have explored the spin dynamics in DyScS@C exhibiting among the highest blocking temperature ( ) reported. Through our computational analysis, we reveal that while the fullerene cage enhances crystal field splitting and provides structural stability without significantly contributing to spin-relaxation driving low-energy phonons, the internal ionic motion emerges as the primary factor controlling spin relaxation and limiting blocking temperature. This computational investigation into the spin dynamics of EMF-based SMMs provides key insights into their magnetic behaviour and suggests potential strategies for improving their performance towards futuristic SMMs.
本研究利用完全活性空间自洽场（CASSCF）结合密度泛函理论（DFT）计算，对基于富勒烯的单分子磁体（SMM）中的自旋 - 声子耦合机制进行了研究。虽然基于镧系元素的SMM，特别是那些含有镝（Dy）离子的SMM，因其令人印象深刻的阻塞温度和弛豫势垒而闻名，但内嵌金属富勒烯（EMF）为在刚性碳笼内容纳低配位镧系元素提供了一个独特的平台。我们研究了DyScS@C中的自旋动力学，其具有已报道的最高阻塞温度（ ）。通过我们的计算分析，我们发现虽然富勒烯笼增强了晶体场分裂并提供了结构稳定性，但对驱动低能声子的自旋弛豫没有显著贡献，而内部离子运动成为控制自旋弛豫和限制阻塞温度的主要因素。这项对基于EMF的SMM自旋动力学的计算研究为其磁行为提供了关键见解，并为改进其面向未来SMM的性能提出了潜在策略。
