Precipitation kinetics of superparamagnetic nickel and cobalt crystals in silicate glasses controlled by redox potential

氧化还原电位控制硅酸盐玻璃中超顺磁性镍钴晶体的沉淀动力学

• 批准号: 316146333
• 负责人: Professor Dr.-Ing. Joachim Deubener
• 金额: --
• 依托单位: Fraunhofer-Institut für Mikrostruktur von Werkstoffen und Systemen (IMWS)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2019-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/316146333?language=en
• 关键词: Precipitation; kinetics; superparamagnetic; nickel; cobalt

Colloids of the transition metals cobalt and nickel of high number densities (>1E20 m-3) shall be synthesized via redox potential induced precipitation in silicate glasses. The initial focus of this research is constituted by the kinetics of these processes, as well as by the analysis of microstructure-property relationships. Due to the nanosized scale of the precipitated metal phases, plasmon resonance based phenomena and, in particular, super-paramagnetic behavior can be expected from these novel metal-glass composites. In order to tailor the materials' microstructure, the kinetics of the involved precipitation and crystallization processes have to be controlled. Preliminary work showed a feasible path to produce a nanoscaled microstructure via complex redox reactions, which has been adopted from enamel technology. Therefore, it is anticipated that within this project, an alternative synthesis route for the generation of magnetic Co- and Ni- nanoparticles can be established, which is different from the usually used synthesis schemes (e.g., chemical precipitation reac-tion or hydrothermal synthesis). If nanoparticles are established via the envisioned precipitation route, they are intrinsically embedded in the silica matrix, thus protected against corrosive attack (oxidation), and bear a high potential e.g. for information storage applications. A huge level of scientific knowledge gain is expected by the project, since the factors which control the involved solution, degradation and precipitation reactions of Ni and Co metals are not reported in literature yet. This scientific "new ground" is broken via a combination of work packages considering both glass technology - on the side of glass syntheses - and micro-structural diagnostics - on the side of nanoanalytics - to gain a knowledge-based understanding of the relevant precipitation phenomena. The planned project may lead to a generalization of the ceramization of glasses, since through a control of the redox state of glass constituents, nanoscaled metal phases in a silicate network are expected to be synthesized. In contrast to the standard state-of-the-art glass ceramming technologies that rely on the crystallization of functional oxide phases via the preliminary precipitation of nucleation agents, this approach is entirely novel. It can be expected that it can provide a basis for the development of novel functional composite materials.

过渡金属钴和镍的高数密度（> 1 E20 m-3）胶体应通过氧化还原电位诱导沉淀在硅酸盐玻璃中合成。本研究的最初重点是由这些过程的动力学，以及通过分析微观结构与性能的关系。由于沉淀的金属相的纳米尺度，可以从这些新型金属-玻璃复合材料中预期基于等离子体共振的现象，特别是超顺磁性行为。为了定制材料的微观结构，必须控制所涉及的沉淀和结晶过程的动力学。初步工作表明，通过复杂的氧化还原反应产生纳米级微观结构的可行途径，这已从搪瓷技术中采用。因此，预期在该项目内，可以建立用于产生磁性Co-和Ni-纳米颗粒的替代合成路线，其不同于通常使用的合成方案（例如，化学沉淀反应或水热合成）。如果纳米颗粒是通过设想的沉淀途径建立的，则它们固有地嵌入在二氧化硅基质中，从而免受腐蚀侵蚀（氧化），并且具有高潜力，例如用于信息存储应用。该项目预计将获得大量的科学知识，因为控制Ni和Co金属的溶解、降解和沉淀反应的因素尚未在文献中报道。这一科学“新领域”通过考虑玻璃技术（玻璃合成方面）和微观结构诊断（纳米分析方面）的工作包组合而被打破，以获得对相关沉淀现象的基于知识的理解。计划中的项目可能会导致玻璃陶瓷化的推广，因为通过控制玻璃成分的氧化还原状态，预计将合成硅酸盐网络中的纳米级金属相。与依赖于通过成核剂的初步沉淀使功能氧化物相结晶的标准最先进的玻璃陶瓷化技术相比，这种方法是完全新颖的。有望为新型功能复合材料的开发提供依据。