Magnetron Sputtered Non-Toxic and Precious Element-Free Ti-Zr-Ge Metallic Glass Nanofilms with Enhanced Biocorrosion Resistance

TL;DR

This study develops non-toxic Ti-Zr-Ge metallic glass nanofilms via magnetron sputtering, demonstrating their enhanced biocorrosion resistance and stability for biomedical nanocoatings, with detailed structural and electrochemical analysis.

Contribution

It introduces a novel Ti-Zr-Ge metallic glass composition fabricated by magnetron sputtering, showing superior corrosion resistance and stability for biomedical applications.

Findings

Ti-Zr-Ge nanofilms exhibit excellent corrosion resistance at 37°C.

The oxide layer contains TiO₂, TiOₓ, and ZrOₓ, contributing to stability.

Significant increase in oxide interface resistance enhances corrosion protection.

Abstract

The chemical composition and structural state of advanced alloys are the decisive factors in optimum biomedical performance. This contribution presents unique Ti-Zr-Ge metallic glass thin-film compositions fabricated by magnetron sputter deposition targeted for nanocoatings for biofouling prevention. The amorphous nanofilms with nanoscale roughness exhibit a large relaxation and supercooled liquid regions as revealed by flash differential scanning calorimetry. Ti\textsubscript{68}Zr\textsubscript{8}Ge\textsubscript{24} shows the lowest corrosion (0.17 \textmu A cm\textsuperscript{\textminus2}) and passivation (1.22 \textmu A cm\textsuperscript{\textminus2}) current densities, with the lowest corrosion potential of \textminus0.648 V and long-range stability against pitting, corroborating its excellent performance in phosphate buffer solution at 37 {\textdegree}C. The oxide layer is comprised of TiO\textsubscript{2}, TiO\textsubscript{\emph{x}} and ZrO\textsubscript{\emph{x}}, as determined using X-ray photoelectron spectroscopy by short-term ion-etching of the surface layer. The two orders of magnitude increase in the oxide and interface resistance (from 14 to 1257 {\textOmega} cm\textsuperscript{2}) along with an order of magnitude decrease in the capacitance parameter of the oxide interface (from 1.402 x 10\textsuperscript{\textminus5} to 1.677 x 10\textsuperscript{\textminus6} S s\textsuperscript{n} cm\textsuperscript{\textminus2}) of the same composition is linked to the formation of carbonyl groups and reduction of the native oxide layer during linear sweep voltammetry.