Applied Surface Science, Vol.254, No.15, 4439-4443, 2008
Effects of substrates on the structure and dielectric properties of Ba(Sn0.15Ti0.85)O-3 thin films
Ba(Sn0.15Ti0.85)O-3 (BTS) thin films were grown on Pt(111)/Ti/ SiO2/Si and LaNiO3( LNO)/ Pt(111)/Ti/SiO2/Si substrates by a sol-gel processing technique, respectively. The BTS thin films deposited on annealed Pt(111)/Ti/SiO2/Si and annealed LNO/Pt(111)/Ti/SiO2/Si substrates exhibited strong (111) and perfect (100) orientations, respectively. The BTS thin films grown on un-annealed Pt(111)/Ti/SiO2/Si substrates showed random orientation with intense ( 1 1 0) peak, while the films deposited on un-annealed LNO/Pt(111)/Ti/SiO2/Si substrate exhibited random orientation with intense (100) peak, respectively. The dielectric constant of the BTS films deposited on annealed Pt(111)/Ti/SiO2/Si, annealed LNO/Pt(111)/Ti/SiO2/Si, un-annealed Pt(111)/Ti/SiO2/Si and un-annealed LNO/Pt(111)/Ti/SiO2/Si substrates was 512, 565, 386 and 437, respectively, measured at a frequency of 100 kHz. A high tunability of 49.7% was obtained for the films deposited on annealed LNO/Pt(111)/Ti/SiO2/Si substrate, measured at the frequency of 100 kHz with an applied electric field of 200 kV/cm. The high tunability has been attributed to the (100) texture of the films and larger grain sizes. (c) 2008 Elsevier B.V. All rights reserved.