Structure and Microwave Dielectric Properties of Sm(2− x )/3Li x TiO3

The structural evolution, and microwave dielectric properties of \text Sm _{( 2 - x ) \mathord / \vphantom ( 2 - x ) 3 3} \text Li _x \text TiO ₃ Missing dimension or its units for \kernceramics ( x  = 0.0 ≤  x  ≤ 0.5) were investigated in this work. X-ray diffraction (XRD) results show that samples with x  > 0.3 exhibit a single perovskite phase. Impurity phases of Sm ₂ Ti ₂ O ₇ and TiO ₂ appear and their amount increases with the decrease of x when x  ≤ 0.3. TEM observation indicates that the A-site is ordered in x  = 0.5, but not in x  = 0.3). The dielectric constant decreases with the increase of x for 0.1 ≤  x  ≤ 0.4 and then increases with further increase in x up to x  = 0.5. The Q × f value decreases with the decrease of x due to the increased occurrence of Sm ₂ T ₂ O ₇ secondary phase, defects and twinning boundaries. The temperature coefficient of resonant frequency is negative and its absolute value decreases greatly with the decrease of x value.