Sergiy Borodin

• Dr. rer. nat
• Project Manager at Singulus Technologies AG, Kahl am Main

The study of high temperature oxidation processes depends mainly on ex situ investigations after the high temperature process is completed. In this study Ambient Pressure Photoelectron Spectroscopy was used to investigate its potential for an in situ analysis of the underlying mechanisms of selective oxidation occurring during high temperature anne...

In different production steps steels are exposed to high temperature either in reducing condition (for e.g. N 2 -H 2 during recrystallization annealing) or in oxidizing environments (e.g. during hot rolling and cooling after hot rolling). These processes are accompanied by external and internal oxidation, which can affect further processing steps....

Rust Resistance The rusting of iron and steel can be prevented through the addition of 11% or more chromium. The addition of molybdenum can enhance the corrosion resistance, with a complex interplay between the Cr and Mo atoms. However, if chemical variations exist, corrosion can still occur in localized regions or if the surface layer is mechanica...

Oxides formed by electrochemical treatment of metals frequently have properties and structures very different from the respective bulk oxides. Here, electronic structure and chemical composition were investigated for the oxide formed on polycrystalline zinc after electrochemical oxidation, and after subsequent reduction, in a Na2CO3 electrolyte. Ph...

As we could recently show, scanning Kelvin probe force microscopy (SKPFM) is a very promising and powerful tool for the in situ investigation of filiform corrosion. Here we present how the underlying processes, namely the galvanic coupling of active head and intermetallic particles, can be visualised by performing SKPFM experiments under gas change...

Dealloying is widely utilized but is a dangerous corrosion process as well. Here we report an atomistic picture of the initial stages of electrochemical dealloying of the model system Cu(3)Au (111). We illuminate the structural and chemical changes during the early stages of dissolution up to the critical potential, using a unique combination of ad...

The grain boundary oxidation mechanism in hot rolled chromium manganese steels during heat exposure at 700 degrees C was mathematically modeled. Given a fixed exposure time, the migration of the atomic species (iron, oxygen, chromium and manganese) has been calculated with the parabolic rate equation for diffusion. After each small time step, the d...

We discuss how kinetic effects can be utilized to prepare polar ZnO(0001)−Zn surfaces as very well defined and single-crystalline surfaces by hydroxide stabilization of the polar face via a wet chemical etching process in 3N NaOH. An in situ AFM imaging study of the etching process is presented. In addition, measurement and analyses of grazing inci...

Gold nanoparticles with diameters ranging from 3.2 to 9.7 nm were prepared on an ultrathin anodic aluminum film by means of molecular beam deposition. Coverages ranging from 17.9% to 48.5% and the subsequent anodic anodization behavior were studied. Further oxide growth does not completely cover the gold nanoparticles but takes place preferentially...

An Al/Ta bilayer specimen prepared by a successive sputter-deposition of a 150 nm tantalum layer and a 180 nm aluminium layer onto a silicon wafer is anodically processed in a sequence of steps in oxalic acid electrolytes, at voltages of up to 53 V, which generates a 260 nm alumina film with well-ordered nanoporous structure. Further potentiodynami...

A combined approach of pH-dependent in-situ AFM topography and ex-situ LEED studies of the stability and dissolution of single-crystalline ZnO(0001)-Zn surfaces in aqueous media is presented. Hydroxide-stabilized and single-crystalline ZnO(0001)-Zn surfaces turned out to be stable within a wide pH range between 11 and 4 around the point of zero cha...

Two different approaches under ambient conditions were developed for the preparation of clean, non-reconstructed, single crystalline ZnO(0001)-Zn surfaces. The surface preparation by a wet chemical etching procedure was compared with the same treatment in combination with a subsequent heat treatment in humidified oxygen atmosphere. Depending on the...

In order to understand the initial oxidation of Fe-Cr alloys a single crystal of Fe-15Cr (100) was oxidized at 440°C under controlled oxygen partial pressure in a UHV system and the surface morphology was observed using in situ STM (basic pressure 1×10−10 mbar); in addition, polycrystalline Fe&15Cr was oxidized at 400°C in an IR-furnace in atmosphe...