Ultrahigh anharmonicity low-permittivity tunable nanocrystalline thin-film BaTi2O5

Low-Temperature Dielectric Response of Strontium Titanate Thin Films Manipulated by Zn Doping

“…As seen in Figure 3c, the temperature variation of nr shows the peak similar to that observed in ε'(T) dependence with the peak temperature decreasing with increasing Zn content. Concerning the relative tunability values, they are close to each other for all the films under study in the T range above 100 K and are evidently enhanced by Zn doping below 100 K. As a result, the peak tunability On the other hand, reduced permittivity is desirable for impedance matching of tunable dielectric components as well as for a decrease in capacitance-induced delays [17]. Therefore, we checked the dielectric tunability of Zn-doped ST films under 125 kV/cm at 10 kHz and compared it to that of similarly prepared undoped SrTiO 3 film, as shown in Figure 3c.…”

“…The temperature dependence of the dissipation factor of Zn-doped ST films shown in Figure 3b presents up to three peaks at ~17, ~100, and ~185 K. The tanδ magnitude is rather low, staying between 0.3% and 0.6% for all the films, with the only exception being a tanδ value increase up to 1% at around 100 K for SrTi0.95Zn0.05O3−δ film. On the other hand, reduced permittivity is desirable for impedance matching of tunable dielectric components as well as for a decrease in capacitance-induced delays [17]. Therefore, we checked the dielectric tunability of Zn-doped ST films under 125 kV/cm at 10 kHz and compared it to that of similarly prepared undoped SrTiO3 film, as shown in Figure 3c.…”

“…In particular, ferroelectric-related films with DC electric field dependent dielectric permittivity are used to develop frequency-agile electronic devices such as varactors, microwave filters, resonators, voltage-controlled oscillators, and phase shifters, besides passive components [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. For these applications, in addition to the high tunability of dielectric permittivity, the films should have low loss and reduced permittivity values [15][16][17]. Since the tunability of a ferroelectric material is maximized near its Curie point, incipient ferroelectrics such as SrTiO 3 (ST) are useful at cryogenic temperatures (T), whereas regular ferroelectrics such as BaTiO 3 are more suitable above room T [2,15].…”

“…If loss reduction and tunability enhancement in ST-based thin films are to be achieved, devices utilizing films would have a much more attractive performance coupled with the ability to scale down their size. For impedance matching and shorter capacitance-induced delays, a reduced permittivity is also required [17].…”