Relaxation Of Amorphous Structure Research Articles

Application of Mechanochemically Treated Waste Materials for Water Remediation

The possibility to reuse damaged Fe‐based metallic glasses with heterogeneities in their amorphous structure for wastewater remediation is investigated. Fe81B13.5Si3.5C2 ribbons are treated in a planetary ball mill in order to improve their catalytic behavior. Their efficiency in model Fenton reaction of Methyl orange azo‐dye degradation is registered. It reveals significant variations of their performance as a result of material transformation under mechanical treatment. Detailed physicochemical analysis is made to follow material changes after ball milling and catalytic tests. It is obtained that the formation of local atomic Fe‐rich and Fe‐deficit clusters randomly distributed in the amorphous alloy is highly beneficial for increasing catalyst dye degradation ability. Catalytically active centers in studied redox reaction are Fe‐rich clusters due to their strong affinity for donating electrons. Additional important result of this study is that mechanochemical treatment of metallic glasses at appropriate conditions can lead to material homogenization and relaxation of amorphous structure, as it can be observed after temperature annealing. This study demonstrates the possibility to apply mechanochemical method for rearrangement of the amorphous structure of damaged metallic glasses. Such waste materials can be in fact successfully reused as green and sustainable catalysts for effective purification of contaminated industrial waters.

DSC studies of finemet-type glass-coated microwires

Effect of cyclic annealing on the Curie temperature, T C, of Fe 71.8Cu 1Nb 3.1Si 15B 9.1 glass-coated microwires has been investigated. T C of the initially amorphous alloy strongly depends on annealing conditions. Monotonic increase of T C from 579 up to 591 K related with the relaxation of amorphous structure was found during annealing at 633 K. After a certain annealing time in the temperature range 713–813 K, T C splits into two Curie temperatures with values higher ( T C1) and lower ( T C2) than that of the initial state. Further increase of the annealing time, t ann, tends to increase T C1 and decrease T C2. Such peculiar behavior is related with the decomposition of the amorphous matrix and the beginning of the devitrification process.

Structural, mechanical and magnetic properties in heat-Treated Fe73.5Si22.5-xBxNb3Cu1(6≤ x ≤ 12) alloy ribbons

The evolution of structural (X-ray, Mössbauer spectroscopy), mechanical (Young's modulus, ΔE effect) and magnetic (hysteresis loops) properties of Fe 73.5 Si 22.5-x B x Nb 3 Cu 1 (6 ≤ x ≤ 12) alloy ribbons is followed after heating at increasing temperatures, T a , up to full devitrification of the amorphous precursors into a nanocrystalline state. Overall modifications in structure correlate with magnetic and mechanical characteristics, which are analyzed through the induced changes in parameters as internal stress and magnetostriction. Relaxation of amorphous structure (T a ≈ 440 °C) results in magnetic softening and increase of ΔE effect. First stages of crystallization (T a ≈ 480 °C), including a Cu clustering, induces a relative magnetic hardening and reduction of ΔE effect. Optimum nanocrystalline state (T a ≈ 540 °C) with the softest magnetic behavior leads to a final increase of Young's modulus. The influence of relative weights of Si and B is also analyzed.