Speaker
Mr
Paitoon Boonsong
(Advanced Ceramics Laboratory, Ubon Ratchathani University, Ubon Ratchathani, THAILAND 34190)
Description
Ferroelectric glass-ceramics of the Na${}_2$O-BaO-Nb${}_2$O${}_5$-SiO${}_2$ system were obtained from controlled crystallization process performed on the parent glass of composition 20Na${}_2$O-10BaO-30Nb${}_2$O${}_5$-40SiO${}_2$. Nd${}_2$O${}_3$ doping content was varied in the range 0, 0.1 and 0.5 mol%. The glass samples were prepared via a conventional melting method at 1500 $^{\circ}$C in the platinum crucible for 2 hr following by splashed-quenching on the stainless steel plate. Thermal properties of the as-quenched sample were studied by DTA/TG technique and the results showed the possible crystallization peak at 740 $^{\circ}$C and this was selected as the treatment temperature. Heat treatment process was employed for production of glass-ceramic which is performed in the electrical furnace at selected temperature. The obtained glass-ceramic specimens were investigated in terms of the crystalline phase formation, volume fraction, bulk density and dielectric properties. The results of phase identification using XRD revealed that NaNbO${}_3$ and Ba${}_2$NaNb${}_5$O${}_{15}$ were the dominant crystalline phases for all doped samples. The volume fractions of the crystallites are noticeably increased with the Nd${}_2$O${}_3$ content. Bulk densities of the glass-ceramic samples are higher than that of the related as-quenched glass. The dielectric constants measured at room temperature at various frequencies for doped glass-ceramics seemed to be affected by the presence of Nd$^{3+}$ ion.
Authors
Dr
Anusorn Niyompan
(Advanced Ceramics Laboratory, Ubon Ratchathani University, Ubon Ratchathani, THAILAND 34190)
Mr
Paitoon Boonsong
(Advanced Ceramics Laboratory, Ubon Ratchathani University, Ubon Ratchathani, THAILAND 34190)
Co-author
Dr
Rungnapa Tipakontitikul
(Advanced Ceramics Laboratory, Ubon Ratchathani University, Ubon Ratchathani, THAILAND 34190)
