Giant dielectric response with metastable phase crystallization from Ba1-Ca Ti2O5 glasses

Abstract Ba1 −xCaxTi2O5 glasses (0 ≤ x ≤ 0.80) were fabricated by containerless processing. All glasses had two crystallization temperatures, Tx1 and Tx2. The dielectric constant (e′) increased at Tx1 and the large value was maintained during the existence of the first crystallized phase in the lightly Ca2 +-doped region (0 ≤ x ≤ 0.15). An instantaneous jump of e′ at Tx1 was observed when 0 ≤ x ≤ 0.07, but there was no jump when 0.10 ≤ x ≤ 0.15. Synchrotron X-ray diffraction measurements showed that in the region 0 ≤ x ≤ 0.15, the first crystallized phases were nearly isomorphous with α-BaTi2O5; the lattice constant decreased with the Ca2 + content when 0 ≤ x