| Summary: | 碩士 === 東海大學 === 化學工程與材料工程學系 === 99 === ABSTRACT
In this dissertation, we reported on the microstructures, dielectric properties, and magnetic properties of the (x) (Bi3La0.5Nd0.5)Ti3O12-(1-x) (Ni0.5Zn0.5)Fe2O4 magnetoelectric composites and thin films, where x=0, 0.2, 0.4, 0.6, 0.8, and 1.0, which were prepared by sol-gel and solid state methods.
The (x) BLNTO-(1-x) NZFO composites were sintered between 850°C and 1250°C for three hours in the air. The relative densities of the composites are beyond 80% and all of them possess both ferroelectric and ferromagnetic phases. At the same BLNTO percentage, the thermal expansion coefficients of composites prepared by sol-gel method are lower than those of composites prepared by solid state method. The dielectric constant will increase, but the saturation magnetization will decrease as the percentage of BLNTO increases. Both the dielectric constant variation trends of the B4N1(x=0.8) composite prepared by sol-gel method and the B1N4(x=0.2) composite prepared by solid state method are affected by the applied magnetic field.
At the same frequency, the dielectric constant of each composite thin film will decrease as the percentage of NZFO increases. There is a relative low value of dielectric constant at about 6 MHz. The dielectric loss will increase with increasing frequency and there is a relative low value of dielectric loss at about 6 MHz.
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