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High-quality Yttrium iron garnet (YIG) films with crack-free surface and improved magnetic performance were grown on platinum (Pt)-buffered Si substrates by chemical solution deposition technique. The saturation magnetization of obtained YIG films can reach 124 emu/cm³, which was the 88% theoretical value of YIG single crystal. The effects of annealing condition were also discussed. When annealed at 750°C for 1 h, YIG films showed a very small coercive field of 12 Oe and the peak-to-peak ferromagnetic resonance linewidth can be as low as 95 Oe at 9.10 GHz. The results demonstrated that YIG films prepared on Pt-buffered Si substrates can be beneficial to the application of YIG films to integrated devices. [ABSTRACT FROM AUTHOR]

Ba(Sr,Ti)O3 material presents a remarkable property that lies in the possibility to change the permittivity by applying a DC electric field, i.e., BST is a tunable material. That makes BST a very interesting material for the development of reconfigurable devices in microelectronics. In this study, we focus our work on Ba(Sr,Ti)O3 with Ba/Sr = 30/70, the films are deposited by radio-frequency magnetron sputtering on Al2O3 (0001). A buffer layer of TiOx is used to control the film orientation. The influence of this buffer layer on the dielectric properties, the interfaces quality with respect to the film thickness, and the temperature is analyzed. An increase of 30% of the relative permittivity was measured and a tunability of 50% was attained at 300 KV/cm. The dielectric measurements on BST/ TiOx as a function of the temperature show a shift of the Curie temperature (Tc = - 40°C) in comparison to BST without TiOx layer (Tc = - 80°C). We demonstrate that the Curie temperature does not correspond to the maximum permittivity. The important stress measured on the films (930 MPa) could explain this behavior. [ABSTRACT FROM AUTHOR]

Perovskite Ba0.6Sr0.4TiO3 ( BST), pyrochlore Bi1.5Zn1.0Nb1.5O7 ( BZN), and hetero layered BZN/BST films have been directly grown on high resistivity ( HR)- Si substrates by radio frequency magnetron sputtering. The microwave properties (up to 50 GHz) of all the films are evaluated by fabricating coplanar waveguide configuration. Experimental results showed that the BZN layer helped in tailoring the dielectric constant and reducing the loss tangent significantly. Moreover, the resulting BZN/BST/HR-Si films show moderate permittivity (~258) and tunability (~15.63%, 200 kV/cm), and low microwave loss (~0.0175) at 2 GHz and their microwave properties (1-50 GHz) potentially could be made suitable for integrated microwave tunable devices. [ABSTRACT FROM AUTHOR]