The microwave dielectric properties of AB2O6 compounds, where A=Ca, Mg, Mn, Co, Ni, or Zn, and B=Nb or Ta, were investigated. All samples were prepared using the mixed oxide method. In particular, AB2O6 compounds with Mg2+ and Zn2+ revealed very good dielectric properties with respect to dielectric resonator applications. However, their temperature coefficient of resonant frequencies should be modified. It was found that the electronegativity of AB2O6 compounds is relevant to their dielectric constant. The temperature coefficient of resonant frequency was discussed in terms of volume contraction.

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Periodically polarity inverted (PPI) ZnO templates were fabricated using molecular beam epitaxy by employing MgO buffer layers. The polarity of ZnO film was controlled by the transformation of crystal structure from hexagonal to rocksalt due to the thickness of the MgO buffer layers. The polarity of ZnO in the PPI template was confirmed by AFM and PRM measurement. Higher growth rate and lower current value under positive supplied voltage in the region of Zn-polar were measured with comparing to that of O-polar. Holographic lithographic technique was employed for the realization of submicron pattern of periodical inverted polar ZnO over large area. After reaction using a carbothermal reduction, spatially well-separated ZnO nanorods with pitch of submicron were only observed in the Zn-polar regions. The possible reason for the difference of surface characteristics was considered as being due to the configuration of dangling bonds according to polarity.

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