The Magnetic Properties of Manganese(II) Phthalocyanine

The magnetic transition from the ferro- to the para-magnetic state of manganese(II) phthalocyanine (C32H16N8Mn) has been observed by measurements of the magnetic susceptibility, the magnetization and the proton magnetic resonance in the low-temperature range. The positive Weiss constants were obtained from the static susceptibility measurements and the proton magnetic measurements. Moreover, the magnetic-field dependences of the experimental results were found in the low-temperature range. All of those findings confirm the ferromagnetic behavior of this substance in the lower-temperature region. From the measurements of the frequency shift in the resonant circuit of the proton magnetic resonance apparatus, the transition temperature was determined to be 8.6 K. A possible mechanism of long-range ordering was also discussed on the basis of the crystal structure of this substance.