Table 8: Overview of doping dependence of dielectric properties of planar BaxSr1−x TiO3:M (M = Fe, Mg, Y, Ti, Zr) thin film capacitors on microwave ceramic substrates. Maximum values of capacity at zero DC bias, 𝑄 value, and tunability are highlighted by bold type. See Figures 19, 20, 21, 22, and 23 for the sample design and selected, more detailed graphs of C and 𝑄 as functions of T for DC bias from 0 to 10 V.

PLD thin film dielectric in
Pt-BSTO:X-Pt capacitor
Capacity [nF]
@ 0 V and 20°C
𝑄 value
@ 0 V and 20°C
Tunability Δ C / Δ U
[ n F / V ] for Δ U = 1 0 V @ 20°C
T-coefficient
Δ C / Δ U [ n F / K ]
@ 0 V , Δ T = 2 5 - 1 5 C

Undoped BSTO:
BTO89185.50.44
BSTO-0.8172 (5 V)*17 (5 V)*20.70.77
BSTO-0.8 annealed116427.80.46
BSTO-0.6195 (5 V)*29 (5 V)*24.7−4.6
BSTO-0.5 to 0.85
Gradient H. Christen, ORNL, USA
112 (5 V)*22 (5 V)*10.5−1.14
Doped BTO:
BTO:Fe2O3(0.5%)83155.60.41
BTO:Fe2O3(1%)2061817.00.49
BTO:Fe2O3(2%)35581.2−0.3
BTO:Fe2O3(5%)24490.4−0.11
BTO:MgO(1%)98 (5 V)*31 (5 V)*6.6−0.08
BTO:MgO(2%)40 (5 V)*14 (5 V)*0.5−0.08
BTO:Y2O3(1%)49172.90.19
BTO:Y2O3(2%)1491812.20.39
BTO:Y2O3(2%) annealed118269.40.43
BTO:TiO2(3%)90 (5 V)*23 (5 V)*9.0−0.003
BTO:TiO2(3%) annealed136389.80.09
BaTi0.8Zr0.2O378245.5−0.6

*For these samples the maximum DC bias was 5 V, because of the leackage currents.