Ni₆₀Nb₄₀ Nanoglass for Tunable\nMagnetism and Methanol Oxidation

Abstract

Local\ncontrol in microstructure in nanocrystalline solid materials\nemerges from their property and reactivity. Similar observation is\nalso seen for nanostructured glassy alloys accounting for enhanced\nproperties of nanoglass compared to their metallic glass analogue.\nHere, we show synthesis and detailed microstructural characterization\nof a Ni₆₀Nb₄₀ nanoglass starting from amorphous\nnanoparticles and compared the results with a melt-spun ribbon (MSR)\nof identical atomic composition. The effect on the magnetic property\nduring the consolidation of glassy nanoparticles at different uniaxial\npressures to create such nanoglass is studied in detail. While nanoglass\nshowed ferromagnetic behavior at every compaction pressure, the MSR\nalways remained paramagnetic although its density was comparable.\nNot only that the amorphous phase of these two materials behaves differently,\nwhen annealed above their crystallization temperature, annealed nanoglass\nresponded distinctly differently compared to the MSR confirming non-identical\nlocal structure even after heat treatment. Taking advantage of the\npresence of amorphous nickel, the enhanced response of the glassy\ninterface in the nanoglass, we tested these materials for the electrochemical\nmethanol oxidation reaction (MOR) in alkaline medium and found that\nthe nanoglass offers reasonably high MOR capacity compared to the\nMSR. The structure–property correlation in the context of energy\napplication using such nanoglass materials is tested for the first\ntime.