Interplay of structural and electronic properties and their impact on thin films of metal-free organic radicals (Prolongation).

• Applicant: Professorin Dr. Maria Benedetta Casu
• Subject Area: Physical Chemistry of Solids and Surfaces, Material Characterisation ; Experimental Condensed Matter Physics
• Term: since 2018
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 394233453

I intend to intercorrelate the structure with the film properties of (poly)radical thin films, also addressing their film stability. I want to tune the film structure, also using different functional groups, i.e., designing the chemical structure of the films, tuning the growing conditions, and investigating the impact on the film proprieties. We are going to evaporate radicals, diradicals, and triradicals. After optimizing a growth recipe to obtain films and monolayers of intact radicals, the systems will be fully characterized, intercorrelating structural, and electronic properties. The investigations will be mainly performed with X-ray based techniques also by using synchrotron radiation. I will also investigate how the strength of the interaction between the (poly)radical and the substrate influences not only the formed interface but also the growth modes and the film processes of the radical thin films. Assessing the film stability is important for two main reasons: 1) to understand the chemistry of the films once exposed to air before performing electron spin resonance (ESR) spectroscopy that is the traditional (ex-situ) technique used for radicals. 2) To define the film stability in an environment simulating a working device. We have also developed a protocol to investigate the effects of air exposure on the radical thin films and we will use it.Within the present project, I intend to extend our X-ray magnetic circular dichroism (XMCD) investigations performing magnetization measurements depending on the field to identify the magnetic character of the films and if possible, to obtain a hysteresis curve for magnetization because this will give a clear indication on the magnetic character of the system.

• DFG Programme: Research Grants
• International Connection: Italy, Spain, USA
• Cooperation Partners: Dr. Arrigo Calzolari; Dr. Núria Crivillers; Professor Dr. Andrzej Rajca