Anisotropic photo-induced magnetism of a $Rb_j Co_k [Fe(CN)_6]_l \cdot n H_2 O$ thin film

TL;DR

This study demonstrates anisotropic photo-induced magnetism in a Rb-Co-Fe cyanide thin film, where magnetization changes depend on the film's orientation relative to an external magnetic field, revealing potential for novel device applications.

Contribution

It introduces a new orientation-dependent phenomenon in photo-induced magnetism within a low-dimensional cyanide-based thin film system.

Findings

Magnetization increases when surface is parallel to the magnetic field upon irradiation.

Magnetization decreases when surface is perpendicular to the magnetic field upon irradiation.

Orientation controls the sign of the photo-induced magnetization change.

Abstract

A magneto-optically active thin film of Rb$_{j}$Co$_{k}$[Fe(CN)$_{6}$]$_{l}$ $\cdot$$n$H$_{2}$O has been prepared using a sequential assembly method. Upon irradiation with light and at 5 K, the net magnetization of the film increased when the surface of the film was oriented parallel to the external magnetic field of 0.1 T. However, when the surface of the film was perpendicular to the field, the net magnetization \emph{decreased} upon irradiation. The presence of dipolar fields and the low-dimensional nature of the system are used to describe the orientation dependence of the photo-induced magnetization. The ability to increase or decrease the photo-induced magnetization by changing the orientation of the system with respect to the field is a new phenomenon that may be useful in future device applications.