Publications

We detect a single spin nuclear magnetic resonance (NMR) by monitoring the intensity modulations of a selected hyperfine line in the electron spin resonance (ESR) spectrum. We analyse the power spectrum of the corresponding hyperfine intensity and obtain the nuclear magnetic resonance (NMR) spectrum. Our process also demonstrates ionization of a molecule with the bias voltage of a Scanning Tunnelling Microscope (STM), allowing detection of NMR even in molecules that are non-radical in their neutral state. We have observed this phenomenon in four types of molecules: toluene, triphenylphosphine, TEMPO and adenosine triphosphate (ATP) showing NMR of H, 13C, 31P and 14N nuclei. The spectra are detailed and show signatures of the chemical environment, i.e. chemical shifts. A theoretical model to account for these data is outlined.

This paper introduces an electrochemical scanning microwave microscopy (EC-SMM), enabling local measurement of electrochemical properties with nanometer spatial resolution and sensitivity down to atto-Ampere electrochemical currents. Its power is demonstrated by studying NiCo-layered double hydroxide flakes, revealing active site locations and providing atomistic insights into the catalytic process. This enabled the analysis of edge effects in this 2D material, including localized electrochemical impedance spectroscopy and cyclic voltammetry. Findings elucidate the previously hypothesized processes responsible for localized enhancements in electrochemical activity, while pinpointing essential parameters for tuning the thermodynamics of ion intercalation and optimizing surface adsorption.

This study investigates the OER catalytic performance and stability of a cobalt-based polyoxometalate ([Co4(H2O)2(PW9O34)2]10–, Co4-POM) intercalated within the lamellar space of a layered double hydroxide (LDH). The resulting nanocomposites exhibit enhanced OER efficiency compared to both Co4-POM alone and Co3O4, with excellent stability in near-neutral media. However, in alkaline conditions, the Co4-POM framework experiences hydrolytic instability, leading to the formation of an OER-active, layered cobalt(II/III) oxide in the LDH interlayer.

Permalloy-based thin films are ferromagnetic materials with excellent magnetic properties, and their detection is appealing for several applications. Here, a Scanning Microwave Microscope is used to characterize a 15 nm film permalloy (Py) layer buried below 5 nm Aluminum (Al). An ad-hoc experimental setup for reduced parasitics and high-sensitivity operation proved to be an excellent platform to probe the sample magnetic response with nanometer spatial resolution. In particular, magneto-impedance effects, i.e. the high-frequency electrical impedance change due to an externally applied magnetic field, have been captured at 11.1 GHz by microwave spectroscopy, and subsequently studied for various magnetic field intensities. The achieved combination of microwave tomography, high-resolution imaging, and magnetic response detection is challenging for other characterization tools; this provides the foundation to characterize modern multilayered and nanostructured magnetic devices with this tool.

This study explores spin-crossover (SCO) molecules for molecular magnetism and electronic devices. A new example, [Fe(neoim)2], is introduced, demonstrating both bulk and thin-film capabilities. The material's synthesis, magnetostructural characterization, and high-vacuum sublimation for thin-film formation are investigated. Retention of spin-crossover capabilities, including a rapid light-induced spin transition (LIESST effect) in ultrathin films (15 nm), is observed through X-ray absorption spectroscopy.

This study reports the solution-phase synthesis of porphyrin-fused graphene nanoribbons (PGNRs) featuring metalloporphyrins, demonstrating long chains, a narrow optical bandgap, and high charge mobility. PGNRs enable the fabrication of ambipolar field-effect transistors and single-electron transistors, offering a pathway to engineer electrical and magnetic properties in nanostructures through porphyrin coordination chemistry.