| Traditional magnetic materials have been applied widely in the realms of national defence, scientific research, industrial technologies and daily life, etc. However, their application has great limitation in some special fields of advanced research and technologies because of their necessary process of metallurgy at high temperature, high density, difficulties for subtle molding and machining, waste of magnetic energy, and so on. While organic magnetic materials have great applied potential in some fields which require materials with low density and soft magnetism, such as ultrahigh frequency equipments, high density memory materials, microwave - absorbing materials, micrornation of electron products, space navigation, etc, for their advantages of structural variety, easy preparation using chemical methods, compositive properties of magnetism with mechanism, optical and electronical properties, low waste of magnetic energy, etc.The development and status in quo of organic magnetic materials have been summarized in this paper. The main task has been proposed on the basis of the introduction, which including the synthesis of polymers and complexes containing methyl substituted bithiazole rings, the relationship of their structures and magnetic properties. At the same time, the studies are supposed to contribute to the theoretical research of organic magnetic materials.The synthesis of novel monomer MDABT containing methyl bithiazole rings, three polyimides obtained by condensation of MDABT with dianhydrides, poly (Schiff-base)s prepared by condensation of MDABT and glyoxal and phenyl dialdehydes, the complexes prepared of PMDTEN and PMT1A with Fe2+ ions, PDTEN and PMDTEN with Nd3+ ions are introduced in this paper. The structures of these products were characterized by IR, 1H NMR. The intrinsic viscosities ([η]) of these polymers were measured and the metal contents of the complexes were obtained using three different methods.The heat-resistant properties of polymers were measured by thermo gravimetric apparatus. It is found that the imidation temperature of po!y(amic acid)s are about 200℃, the decomposition temperature in air of polyimides are all above 390℃, the decomposition temperature in air of PMDTEN is 318℃ while that of other three poly(Schiff base)s containing benzene are all above 350℃. These data indicate that these polymers' containing bithiazole rings have good thermal stabilities.The magnetic properties of PDTEN, PMDTEN, PMDTEN-Fe2+, PMTlA-Fe2+, PDTEN -Nd3+ and PMDTEN-Nd3+have been studied. The curves of magnetization versus temperature (M-T) for PDTEN and PMDTEN were measured in an applied field of 20 kOe and the curves of magnetization versus applied field (M-H) are obtained at 4K.It can be concluded from the magnetic data that polymers PDTEN and PMDTEN are diamagnetic, their diamagnetic susceptibilities are not applied field dependent but temperature dependent, which are stable withapplied field changes but increase with the increasing of temperature.The M-T curves of complex PMDTEN-Fe2+ were measured in low applied field of 100 Oe and high applied field of 30kOe and its M-H curve at 2K was obtained. Judging from the shapes of these curves, it can be concluded that PMDTEN-Fe2+ is antiferromagnetic in a low applied field while soft ferromagnetic in high applied field, the remanence magnetization is 0.02emu/g, the coercivity is 90 Oe at 2K.The M-T curve of complex PMT1A-Fe2+ was measured in an applied field of 30kOe and its M-H curve at 4K was obtained. It can be concluded that PMTIA-Fe2+ is antiferromagnetic, the remanence magnetization is 0.013emu/g, the coercivity is 26 Oe at 4K.The magnetic properties of PDTEN-Nd3+ were found to be different from those of complexes containing Fe2+ ions. The M-T curves of PDTEN-Nd3* PMDTEN-Nd3+ in an applied field of 20kOe were obtained. PDTEN-Nd3+ is ferromagnetic at temperature lower than 10K(the transition for PMDTEN -Nd3+ occurs at 7.5K), while it turns into diamagnetic at temperature higher than l0K.The M-H curves for these...
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