Galarreta-Rodríguez Itziar, Liguori Deborah, Garaio Eneko, Muzzi Beatrice, Cervera-Gabalda Laura, Rubio-Zuazo Juan, Gomide Guilherme, Depeyrot Jerome, López-Ortega Alberto
Spanish CRG Beamline at the European Synchrotron (ESRF), B.P. 220, Grenoble F-38043, France.
Instituto de Ciencia de Materiales de Madrid, ICMM-CSIC, Madrid 28049, Spain.
ACS Appl Nano Mater. 2025 Jul 2;8(27):13817-13828. doi: 10.1021/acsanm.5c02139. eCollection 2025 Jul 11.
The nanoscale engineering of doped iron oxide magnetic nanoparticles has attracted significant interest in recent years for high-frequency theragnostic applications, where simultaneous diagnosis and therapy are required. In particular, their ability to generate localized heating under alternating magnetic fields makes them ideal candidates for magnetic hyperthermia, a noninvasive cancer treatment technique. However, understanding the complex interplay between multiple dopant cations and their impact on dynamic magnetic behavior remains a significant challenge. In this work, we present a comprehensive study on how two differently marked cations (Co and Ga) can modify both the magnetic properties of these nanoparticles and their efficiency in heat generation under alternating magnetic fields. To this end, a series of nanoparticles with the formula Co GaFe O (0 < < 0.3) was prepared via thermal decomposition, enabling the production of monodisperse nanocrystals with high crystallinity and precise stoichiometric control. Their exhaustive structural and magnetic characterization confirmed site-selective incorporation of Ga into tetrahedral sites and Co into octahedral sites. Increasing the cobalt content within the gallium-doped framework leads to enhanced magnetocrystalline anisotropy and higher saturation magnetization, both crucial parameters for efficient heat dissipation in magnetic hyperthermia. The study further demonstrates that the dynamic magnetic response of these nanostructures is strongly influenced by the interplay between doping composition, anisotropy, and the amplitude of the applied magnetic field. These findings highlight the effectiveness of nanoscale codoping strategies in fine-tuning magnetic behavior and optimizing the performance of spinel ferrite nanoparticles for advanced biomedical and technological applications, particularly high-frequency magnetic hyperthermia.
近年来，掺杂铁氧化物磁性纳米颗粒的纳米级工程因其在需要同时进行诊断和治疗的高频诊疗应用中而备受关注。特别是，它们在交变磁场下产生局部加热的能力使其成为磁热疗（一种非侵入性癌症治疗技术）的理想候选材料。然而，理解多种掺杂阳离子之间复杂的相互作用及其对动态磁行为的影响仍然是一项重大挑战。在这项工作中，我们对两种不同标记的阳离子（Co和Ga）如何改变这些纳米颗粒的磁性以及它们在交变磁场下的发热效率进行了全面研究。为此，通过热分解制备了一系列化学式为CoₓGa₁₋ₓFe₂O₄（0 < x < 0.3）的纳米颗粒，从而能够生产具有高结晶度和精确化学计量控制的单分散纳米晶体。它们详尽的结构和磁性表征证实了Ga选择性地掺入四面体位置，Co掺入八面体位置。在掺镓框架内增加钴含量会导致磁晶各向异性增强和饱和磁化强度提高，这两个都是磁热疗中有效散热的关键参数。该研究进一步表明，这些纳米结构的动态磁响应受到掺杂成分、各向异性和外加磁场幅度之间相互作用的强烈影响。这些发现突出了纳米级共掺杂策略在微调磁行为和优化尖晶石铁氧体纳米颗粒性能以用于先进生物医学和技术应用（特别是高频磁热疗）方面的有效性。
