Iron Oxide-Coupled Graphite/Fe–Si Steel Structure for Analog Computing from Recycling Principle

Roberto Baca-Arroyo

doi:10.3390/coatings11050607

Roberto Baca-Arroyo

Open Access

https://doi.org/10.3390/coatings11050607

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Abstract

Analog computing from recycling principle for next circular economy scenario has been studied with an iron oxide-coupled graphite/Fe–Si steel structure which was built using recycled waste materials, such as lead pencil and 3% Si steel (Fe–Si steel) foils. Proximity phenomena, such as disordered structure of iron oxide and magnetostriction-induced conduction, inside graphite lattice resulted in functional properties to advance analog architectures. Thermal oxidation was the synthesis route to produce iron oxide as coating film on Fe–Si steel foil, whose structure properties were validated by Raman spectroscopy where phase formation of hematite, α-Fe2O3, resulted as iron oxide thin-film. Three graphite layers with different compositions were also analyzed by Raman spectroscopy and used for studying electrical conduction in Fe–Si steel/α-Fe2O3/graphite structure from current–voltage plots at room temperature.

Highlights

Oxide-Coupled Graphite/Fe–Si SteelNowadays, sustainable polices and strategies are based on transition from a linear to a circular economy model, where worldwide research has presented an upward trend since 2015, matching with the aims of the 2030 Agenda [1]
This section describes how defects in graphite layers and magnetostriction in the Fe–Si steel/oxide interface may be clearly activated at their surface, and how their spatial distribution may define the conducting channel with the change in the current signal injection
It reviews Raman bands and electrical conduction to understand their origin in iron oxide-coupled graphite/Fe–Si steel structure, with emphasis on the evaluation of their physical parameters, and phenomenological description during current signal injection is correlated with exchange phenomena

Summary

Introduction

Oxide-Coupled Graphite/Fe–Si SteelNowadays, sustainable polices and strategies are based on transition from a linear to a circular economy model, where worldwide research has presented an upward trend since 2015, matching with the aims of the 2030 Agenda [1]. Among the targets which must be addressed in the following years is advanced research on consequences of climate change; study efficient waste management to avoid a negative environmental impact; growth of agricultural activities; innovation in sustainable processes, goods, and services; and recycling of waste materials [2,3]. In this way, waste will become a valuable resource that must be reintroduced into the manufacturing processes; seeking material attributes (stable chemical properties, electrical, magnetic, and mechanical robustness, etc.). Rather than dismantling a hardware pack into cells and discharging them, they can be separated in modules and studied separately to identify their special properties [5]

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