Structural insights into metal-metalloid glasses from mass spectrometry

Abstract

Despite being studied for nearly 50 years, smallest chemically stable moieties in the metallic glass (MG) could not be found experimentally. Herein, we demonstrate a novel experimental approach based on electrochemical etching of amorphous alloys in inert solvent (acetonitrile) in the presence of a high voltage (1 kV) followed by detection of the ions using electrolytic spray ionization mass spectrometry (ESI MS). The experiment shows stable signals corresponding to Pd, PdSi and PdSi2 ions, which emerges due to the electrochemical etching of the Pd80Si20 metallic glass electrode. These fragments are observed from the controlled dissolution of the Pd80Si20 melt-spun ribbon (MSR) electrode. Annealed electrode releases different fragments in the same experimental condition. These specific species are expected to be the smallest and most stable chemical units from the metallic glass which survived the chemical dissolution and complexation (with acetonitrile) process. Theoretically, these units can be produced from the cluster based models for the MG. Similar treatment on Pd40Ni40P20 MSR resulted several complex peaks consisting of Pd, Ni and P in various combinations suggesting this can be adopted for any metal-metalloid glass.

Anisotropic Plasmon Resonance Enables Spatially Controlled Photothermal and Photochemical Effects in Hot Carrier‐Driven Catalysis

“…Notably, for Au@SiO 2 ‐Pd, a distinct peak at 191 cm –1 was also observed, corresponding to that of surfactant‐capped Pd (Figure 1f). [ 51‐52 ] The structural modification of the nanorods with silica shell and Pd is likely to induce significant shift in the absorbance features of the nanocomposite. To assess the optical response of Au@SiO 2 ‐Pd, the absorbance spectra of the nanocomposite and controls were next probed.…”