Mixed modifier effect in lithium‐calcium borosilicate glasses |
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| Authors: | Yueh‐Ting Shih Jau‐Ho Jean |
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| Affiliation: | Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu, Taiwan |
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| Abstract: | The mixed modifier effect (MME) in the lithium‐calcium borosilicate glasses, which have a composition of 0.4(1?x)Li2O–xCaO]–0.6(1?y)B2O3–ySiO2] with x in the range of 0~1 and y in the range of 0.33~0.83, is investigated. The MME manifests itself as a positive deviation from linearity in the activation energy of electrical conductivity (Eaσ) and as a negative deviation from linearity in the fraction of four‐coordinated boron (N4), glass transition temperature (Tg), dilatometric softening temperature (Td), Vickers microhardness (Hv), dielectric constant (ε), and dielectric loss (tanδ). Moreover, the deviation, which exhibits a maximum at CaO]/(CaO]+Li2O])=0.5, is enhanced with increasing SiO2]/B2O3] ratio in the glass network. The observed MME in Tg, Td, and Hv are attributed to the bond weakening in the network; however, the MME in ε, tanδ, and Eaσ are caused by the obstruction of modifier transport in the glass network. |
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| Keywords: | borosilicate glass mixed modifier effect network transport‐related properties |
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