Structural and Magnetic Properties of Manganese Phthalocyanine Thin Films*

We report on the structural and magnetic properties of manganese phthalocyanine (MnC₃₂N₈H₁₆) thin films. Several 3d transition metal phthalocyanine thin films have been studied with the aim to tune their magnetic properties based on the metal-ion's strong inter-chain interactions. One promising candidate includes manganese phthalocyanine thin films, which were thermally deposited on substrates covered with both insulating and metallic surfaces at different deposition temperatures ranging from room temperature to 260^oC. The diffusion-driven induced structural changes are observed both with x-ray diffraction and atomic force microscopy. While samples deposited at low temperatures with small crystallites tend to follow diamagnetic behavior, thin films of the same material deposited near 230^oC show saturation magnetization and strong deviations from a diamagnetic behavior below 20 K suggesting a structure-induced magnetic transition.