Anisotropic photo-induced magnetism of a sequentially deposited thin films of Rb$_{j}$Co$_{k}$[Fe(CN)$_{6}$]$_{l}$$\cdot$$n$H$_{2}$O*

Using sequential deposition methods, we have generated two different films of Rb$_{j}$Co$_{k}$[Fe(CN)$_{6}$]$_{l}$$\cdot$$n$H$_{2}$O for magneto-optical studies. The synthesis protocol was intentionally varied in order to generate samples with different degrees of surface homogeneity. As a consequence, film \textbf{1} possessed a powder-like rough surface, while film \textbf{2} was a smooth, quasi-two-dimensional film. Upon irradiation at 5 K with an external magnetic field of 200 G perpendicular to the film surface, the magnetization of film \textbf{1} increased, whereas the magnetization of film \textbf{2} decreased. This contrasting behavior is consistent with dipolar field model describing the phenomena* and is related to the novel anisotropy of the photoinduced magnetism in film \textbf{2}, where the photoinduced magnetization increases or decreases depending on the orientation of the film with respect to the external magnetic field.\linebreak *J.-H. Park \emph{et al}., Appl. Phys. Lett. \textbf{85}, 3797 (2004).