The effect of lithium doping on the ferroelectric properties of LST ceramics

The work is devoted to the study of the effect of lithium doping on the structural and electrical properties of ferroelectric ceramics LixSr1-x TiO3. The concentration of lithium dopant varied from x = 0.01 to 0.15. It was found that an increase in lithium during the synthesis leads to phase transformations of the type SrTiO3/TiO2 -> SrTiO3/TiO2/Li2Ti3O7 -> SrTiO3/Li2Ti3O7. According to the data obtained, the capacitance value for samples with a lithium content in the structure x = 0-0.01 is 0.05-0.07*10(-9)F*cm(-1), an increase in lithium concentration to x = 0.05-0.1 in the structure leads to an increase in the capacity value of 0.6*10(-9) F*cm(-1) with a further drop in the frequency range 10(3)-10(5) Hz to 0.05-0.07*10(-9) F*cm(-1), and at a lithium concentration of x = 0.15, the capacitance increases sharply and retains its value throughout frequency range within the range of 0.9-1.2 0.05-0.07*10(-9) F*cm(-1). According to the data obtained, the deviation Delta T from the Curie-Weiss law for the studied ceramics is no more than 4, while the value of the Curie-Weiss constant is characteristic of ferroelectrics. The small value of Delta T indicates that for the initiation of phase transitions from tetragonal/orthorhombic to cubic at temperatures not exceeding 100-110 degrees C.