Electrospun lanthanum-doped barium titanate ceramic fibers with excellent dielectric performance

Abstract

As the pillar material of the electronic ceramic industry, BaTiO3 (BTO) has superior dielectric and piezoelectric properties. In this present work, pure phase BTO and lanthanum-doped Ba(1–x)LaxTiO3 (BLxT) fibers (x=0.003, 0.006, 0.009 and 0.012) were prepared by electrospinning method with polyacetylacetonatotitanate (PAT). All the fibers after heat-treatment were tetragonal phase with good crystallinity; additionally, the tetragonal phase BTO ceramics have better dielectric properties than the cubic ones. BTO fiber (BTOF) and powder (BTOP) were pressed and sintered into ceramic sheets with BTOF having better formability. Compared with BTOP ceramics, BTOF ceramics had obvious micro-capacitance effect, so they had higher dielectric constants at low frequencies (f < 3000 Hz). Therefore, BTOF ceramics were excellent low frequency capacitor materials which could be applied to low frequency filters. The BTOFs were doped with La3+ to further improve the dielectric properties. When the doping concentration was 0.9%, the dielectric constant of BLxT fiber ceramics reached the maximum value of 5100 (25 °C, f = 100 Hz). The downward trend of Curie temperature was more uniform with the increase of La3+ doping amount, pointing to obvious advantages in the manufacturing of temperature-controlled capacitors.