Effect of Applied Electric Field on the Growth and Orientation of Ferroelectric Phase in a Glass

• Main Authors: Yu-Hsien Chen, 陳玉憲
• Other Authors: Jiin-Jyh Shyu
• Format: Others
• Language: en_US
• Published: 2000
• Online Access: http://ndltd.ncl.edu.tw/handle/77378803367549563312

碩士 === 大同大學 === 材料工程研究所 === 88 === Abstract The effect of applied electric field on orientation and growth of PbTiO3 phase in PbO-TiO2-Al2O3-SiO2 glass was studied. The crystal identifies and orientation analysis were investigated by X-ray diffractometry. Dielectric constant was measured by an LCR meter. The results indicated that after nucleation and growth of 40mol%PbO-25mol%TiO2-10mol%Al2O3-25mol%SiO2 glass can be obtain cubic structure and single crystal PbTiO3 phase and remain glass. Applied DC electric field on the nucleation temperature 540℃ then growth at 620℃, can not cause orientation of PbTiO3 crystal in a glass. Applied DC electric field on the nucleation temperature 570℃ then growth at 620℃, can be obtain (h00) preferred orientation of PbTiO3 crystal in surface of the sample, but in internal of the sample we obtained the weak preferred orientation. In the same electric field, the nucleation time of optimum preferred orientation has a maximum value, below or above this value the degree of preferred orientation decrease. Applied a strong electric field, the optimum nucleation time occur in the shower time and applied a weak electric field, the optimum nucleation time occur in the longer time. Applied 1kHz AC and DC electric field cause degree of preferred orientation were similar. When the samples that in the same nucleation time has optimum preferred orientation show the lower dielectric constant. For the sample, which is not applied electric field, the dielectric constant of the sample surface to the internal is not acute change. For the sample, which applied electric field, the dielectric constant decrease when the oriented layer of the sample removed.