Dielectric property of (001) one-axis oriented CaBi₄Ti₄O₁₅-based thin films and their temperature dependence

Abstract

We proposed a thin-film capacitor with a stable temperature coefficient of capacitance (TCC) based on bismuth layer-structured dielectrics, CaBi 4 Ti 4 O 15 . Two types of doping were conducted to lower the dielectric loss in a higher temperature range above 300°C, i.e., Mn ion to compensate for lattice defects in crystalline grains and Bi 12 SiO 20 to form a grain boundary phase were attempted in order to improve the insulating property of the oriented CaBi 4 Ti 4 O 15 films. (00l) one-axis oriented Mn-doped or Bi 12 SiO 20 -doped CaBi 4 Ti 4 O 15 films (with Mn or Bi 12 SiO 20 content up to 3.0 or 1.75%) were fabricated successfully on (111)Pt/ TiO 2 /(100)Si substrates buffered by (001)Ca 2 Nb 3 O 10 nanosheets. These films exhibited a relatively lower loss factor in the temperature range from R.T. up to 400°C. In particular, the behavior of TCC on the Bi 12 SiO 20 -doped CaBi 4 Ti 4 O 15 film was significantly stable, with a change in capacitance, ¦C/C R.T. , within «10% even at 400°C.

Structural and dielectric properties of BaTiO3–Bi(Mg1/2Ti1/2)O3thin films fabricated by chemical solution deposition

“…Significantly larger ¾ r values and comparable «TCC« values were obtained compared with those of thin-film capacitors consisting of bismuth-layer-structured dielectrics (Ca,Sr)-Bi 4 Ti 4 O 15 with " r ' 200. [46][47][48] However, the BT-BMT films with higher BMT content (x = 0.50-0.80) tended to exhibit increasing ¾ r values with increasing temperature, in contrast to the BT film. A definite maximum peak of the ¾ r -T curve was not observed for all of the BT-BMT films.…”