Dielectric Properties of Ba<SUB>1&minus;<I>x</I></SUB>Ca<I><SUB>x</SUB></I>Ti<SUB>2</SUB>O<SUB>5</SUB> Prepared by Arc Melting

Abstract

b-axis-oriented CaO substituted polycrystalline BaTi 2 O 5 , Ba 1Àx Ca x Ti 2 O 5 (BCT 2 , x ¼ 0 to 0.10), was prepared by arc melting. The dielectric property of BCT 2 was investigated by an AC impedance method. The lattice parameters of BCT 2 decreased with increasing CaO content in the range up to around x ¼ 0:08. The remnant polarization (P r ) and coercive electric field (E c ) of polycrystalline BCT 2 at x ¼ 0:08 were 1:6 Â 10 À2 Cm À2 and 0:4 Â 10 6 Vm À1 , respectively. The P r of polycrystalline BCT 2 was larger than that of BaTi 2 O 5 (BT 2 , P r ¼ 0:9 Â 10 À2 Cm À2 ), while the E c of BCT 2 was smaller than that of polycrystalline BT 2 (E c ¼ 0:7 Â 10 6 Vm À1 ). The permittivity of BCT 2 showed the maximum value of 4950 at x ¼ 0:02 and a Curie temperature (T c ) of 736 K. The T c of BCT 2 decreased from 750 to 665 K with increasing CaO content from 0 to 0

Effect of fabrication routes on the properties of Mn-doped BaTi2O5 ceramics

“…Hence, BaTi 2 O 5 is regarded as a very promising lead-free ferroelectric material especially for high temperature applications. 9,10) Since BaTi 2 O 5 is thermodynamically unstable and easily decomposed into BaTiO 3 and Ba 6 Ti 17 O 40 , 11) most research of BaTi 2 O 5 focuses on how to produce high quality BaTi 2 O 5 samples with pure phase [12][13][14][15][16][17][18][19][20][21][22] while few research has systematically investigated the doping effect of BaTi 2 O 5 . However for practical applications ferroelectrics are rarely used in a chemically pure form.…”