Studies of effects of alkali metals on structural change and elastic behaviours of 7056 glass

• Main Authors: CHIA-CHING LEE, 李家慶
• Other Authors: Po-Da Hong
• Format: Others
• Language: en_US
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/17401795574311767806

博士 === 國立臺灣科技大學 === 應用科技研究所 === 101 === This research uses Raman spectroscopy and Brillouin scattering to investigate the influence of amount of alkali metals contributing to 7056 glass, which is used as flux, and the effect on bulk modulus (K), shear modulus (G) and Young’s modulus (E). This research shows that when the amount of alkali metal ions increase, the anionic structure of the glass changes but has no fixed relationship with elastic moduli due to that the factors affecting elastic moduli involve the strength of electric field and density other than the shape of anions. Thus we found the change in amount of Li, Na and K has the trend as the distribution of anionic structures, yet the strength of electric field and size of cations result different fractions of Q species. For Li2O series, since the strength of electric field of Li+ has a strong effect on elastic moduli, elastic moduli increase with the amount of Li+. For Na2O series, when the amount of Na+≧15.4%, the limited increase in density and the decomposition of Q4 and Q3 into low polymerized Q2, Q1 and Q0 in a large scale, hence there is no significant change on elastic moduli when Na+≧15.4%. For K2O series, when the amount of K+≧15.4%, the increase in density is even smaller than which happened on Na2O series and the low polymerised anionic structure is more in amount, associating with the disadvantage on the strength of electric field lf K+, elastic moduli turn to decrease.