Temperature dependency of dielectric properties in epitaxially grown SrBi₄Ti₄O₁₅ films with different orientation

(001)-, (1110), and (105)- oriented SrBi₄Ti₄O ₁₅ films with its c-axis tilted 0, 45 and 55° from the surface normal were epitaxially grown by metal organic chemical vapor deposition and the temperature dependency of the dielectric constant was systematically investigated. Relative dielectric constant, ∈_r, and its temperature dependency increased when the tilting angle of the c-axis from the substrate surface normal increased. Temperature dependency of ∈_r was positive in case of the (105) and (1110) orientation, which is in good agreement with the conventional ferroelectric materials. On the other hand, it became negative for (001) orientation. This shows the orientation dependency of ∈_r in SrBi₄Ti₄O₁₅.