Figure  3a is a bright-field TEM image of the ferroelectric BTO/STO multilayer grown on the (001) MgO substrate. The multilayered structures can be clearly seen from HRTEM images. The inset is a selected area electron diffraction pattern taken at the film/substrate interface with the electron beam direction parallel

to the [100]MgO. The interface relationship of the as-grown BTO/STO multilayer was determined to be (001)BTO/STO//(001)MgO and [100]BTO/STO//[100]MgO with respect to the MgO substrate. Figure  3b is the HAADF-STEM image showing the multilayered structure with sharp interface structures. The electron diffraction, www.selleckchem.com/products/cftrinh-172.html HRTEM, and HAADF-STEM studies on the as-grown multilayer suggest that the films have good single crystallinity and epitaxial quality. Figure DMXAA 3 Cross-sectional bright-field and high-angle annular dark-field image of BTO/STO superlattice thin film. (a) Bright-field image. (b) HAADF-STEM image.

Bar = 200 nm. The CPW test structure was used to determine the high-frequency microwave dielectric properties of the BTO/STO superlattices on (001) MgO. The test structures were fabricated on the bare MgO substrate (reference sample or ‘Ref’) and the multilayer (test sample or ‘Test’) to determine the attenuation and phase constants with and

without the film test samples, which were used to compare the propagation characteristics between the reference and test samples. Figure  4a shows the swept frequency responses for the reference and test samples from 5 to 18 GHz. It can be seen that next the Selleckchem Alvocidib insertion loss contribution from the multilayer is only about approximately 0.17 dB at 5 GHz and approximately 0.45 dB at 18 GHz, indicating that the films have low insertion loss at these frequencies. The inset of Figure  4a is the plot of the relative insertion phase of S 21 for the reference and test samples. The total relative phase of S21 in degrees can be obtained by adjusting the phase of S 21 to a lagging phase. From the magnitude and the relative phase of S 21, we can obtain the attenuation and phase constant for the reference and test samples. Figure  4b shows the calculated and the measured conductor loss and dielectric loss in the sample. It is clearly seen that the calculated and measured total losses are well matched. Figure 4 Plots of (a) insertion loss and (b) calculated and measured conductor loss and dielectric loss The inset in (a) is the relative insertion phase of S 21.