Breaking of Odd Chirality in Magnetoelectrodeposition

Abstract

Electrodeposition under magnetic fields (magnetoelectrodeposition; MED) can induce surface chirality on copper films. The chiral signs of MED films should depend on the magnetic field polarity; namely, the reversal of the magnetic field causes the opposite chiral sign. This represents odd chirality for the magnetic field polarity. However, odd chirality was broken in several MED conditions. This paper makes a survey of breaking of odd chirality in the MED conditions such as low magnetic fields, specific adsorption of chloride ions, micro-electrode, and cell rotation. These results indicate that the ordered fluctuation of magnetohydrodynamic micro-vortices induces the breaking of odd chirality and that the random fluctuation results in the disappearance of surface chirality.

Keywords

• electrodeposition
• magnetic field
• surface chirality
• micro-MHD vortex
• symmetry breaking
• fluctuation