Dual-Channel Dielectric Tunability in Highly Textured BaTi_0.99Fe_0.01O_3−δ Ceramics With Micro-Twin Boundary

Dielectric tunability is widely used in numerous electronic devices, including wavelet filters, lens antennae, and varactors. However, a dielectric device often has only one tunable dielectric constant range, confining the integration of a multi-frequency electronic circuit. Herein, a new kind of dielectric tunable textured BaTi_0.99Fe_0.01O_3−δ ceramics with micro-twin boundaries is proposed for the dual-channel controllable dielectric constants. The relative tunability with the acceptable figure of merit is as large as 76% in the crossover channel, which is superior to that of the most state-of-the-art Ba_xSr_{1 −x}TiO₃ counterparts. This new design strategy offers the possibility of dual-channel filters in one dielectric device controlled by external electric fields. The required external electric field is moderate with the help of reversible micro twins, which is confirmed by first-principles studies. The static magnetic field interference on the dielectric constant is also evaluated, showing the frequency stability of dielectric tunability in a range between 5k and 1 m Hz.