Electric-Field Tunability of Dielectric in Polycrystalline Sr _{1- x} Mn _x TiO ₃ Thin Films

Abstract

The electric-field tunability of dielectric constant (𝜀-𝐸) in Sr1−𝑥Mn𝑥TiO3 films (𝑥 = 0, 0.005, 0.010, 0.020 and 0.030) prepared by the metal organic decomposition method on Pt/Ti/SiO2/Si substrates is studied in the frequency range from 100 Hz to 1 MHz with different Mn contents at different temperatures. The frequencyindependent tunability increases strongly with decreasing the temperature from 300 K to 150 K. The tunability (∼31%) in thin films (𝑥 = 0.005) at 150 K is obtained and the temperature for the same tunability in ceramics is about 60 K lower than the present one. This tunability is comparable with that in one of ferroelectric Sr1−1.5𝑥Bi𝑥TiO3 thin films. Similarly, the well-defined 𝑃 (𝐸) hysteresis loop and 2𝑃r (1.2 𝜇C/cm 2 ) can be obtained at 300 K in Sr1−𝑥Mn𝑥TiO3 films with 𝑥 = 0.005. Both the existence of electric dipole or poled micro domain introduced by the doped Mn 2+ located in the off-center position at Sr sites and the strain between the thin film and the substrate are the origins of the tunable and polar behavior in Sr1−𝑥Mn𝑥TiO3 films.

Fuzzy Comprehensive Evaluation Model of Pulverized Coal Digestibility in Blast Furnace Raceway Based on the Fusion of Subjective and Objective Evidence

“…3,4) According to relevant data, the world's advanced level of PCI is 180-220 kg/t (the PCI rate is 35%-40%), and the world-class level of PCI is 220-240 kg/t (the PCI rate is 40%-45%) at present, while the average PCI of China's key iron and steel enterprises in 2010 is 149 kg/t. 5) Obviously, China's BF injection pulverized coal (PC) technology is lower than the world's advanced level. The difficulty lies in the lack of advanced monitoring methods for the combustion status of the tuyere raceway in the BF.…”

“….................. (5). where, C 1 , C 2 are the first and second radiation constants respectively, C 1 = 3.7418 × 10 − 16 W•m 2 , C 2 = 1.4338 × 10 − 2 m•K; T is the radiator temperature, K; ε (λ,T) is the spectral emissivity of the radiator, dimensionless 20).…”