Anomalous scaling of iron thin film electrodeposited in a magnetic field

Iron thin films were electrodeposited on a copper substrate in FeSO4 aqueous solution under a magnetic field (0–5 T) at 298 K. The surface morphology was observed by the atomic force microscopy (AFM). It was drastically changed from an angular to a wavy shape by superimposing the magnetic field. Moreover, rectangular shaped precipitates were aligned along the magnetic field. The grain size decreased with increasing in magnetic field intensity, B. The AFM image was characterized by the anomalous scaling method in order to quantitatively analyze the magnetic field effect on surface roughness. The roughness exponent, α, and the growth exponent, β, decreased as B increased. The variation of scaling parameters with B may be utilized to improve the surface morphology evolution and the transition of the crystal growth induced by the magnetohydrodynamic convection can be phenomenologically discussed.