oxidelag

Oxidelag, or oxide layer, is a thin film of oxide that forms on the surface of a material through oxidation. It commonly appears on metals, ceramics, and semiconductors when exposed to oxygen or water-containing environments. The composition and structure depend on the underlying material and conditions such as temperature, humidity, and chemical exposure. Growth is driven by diffusion of metal ions outward and oxygen inward; thicker films often follow parabolic kinetics and may evolve into more stable oxides with further processing.

In many metals, oxide layers are protective, forming a passivation layer that slows further corrosion. For example, aluminum forms a dense Al2O3 layer that inhibits metal dissolution, and chromium forms Cr2O3, contributing to the corrosion resistance of stainless steels. Other oxides, such as iron oxides, may be porous or mechanically weak, enabling continued corrosion or spalling. In semiconductors, native SiO2 or thermally grown oxides serve as insulators and gate dielectrics.

Oxidelag can be formed by natural oxidation in air, by thermal oxidation at elevated temperature, or by electrochemical methods such as anodization. Their properties—thickness, density, crystallinity—determine protective capability, optical appearance, and electrical behavior.

Characterization techniques include X-ray photoelectron spectroscopy, transmission electron microscopy, ellipsometry, and Auger electron spectroscopy. Applications span corrosion protection (passivation), catalysis, optics, and microelectronics. Challenges include spallation or breakdown under mechanical or thermal stress, which can expose the underlying material to degradation.