Low-Temperature Sintering of (Ba0.6Sr0.4)TiO3

An addition of just 0.4 wt% Li 2 O to (Ba 0.6 Sr 0.4 )TiO 3 powder was able to reduce the sintering temperature to ≤900°C and produce ceramics with a relative density of 97%. Small amounts of two secondary phases were formed during this process: Li 2 TiO 3 and Ba 2 TiO 4 . The addition of Li 2 O depresses the ferroelectric character of the (Ba 0.6 Sr 0.4 )TiO 3 and, as a result, reduces the permittivity, improves the temperature coefficient of permittivity, and reduces the dielectric losses. The tunability shows no significant variation with Li 2 O concentration and remains between 16.5% and 13.5%. A low-temperature sintering mechanism was proposed. The mechanism involves the intermediate formation of BaCO 3 , its melting and the incorporation of Li + into the BST. The sintering mechanism can be characterized as reactive liquid-phase sintering.