Microwave dielectric properties of ceramics based on CaTiO3–LnMO3 System (Ln–La, Nd; M–Al, Ga)

Structural features and microwave dielectric properties of LnMO3–CaTiO3 samples (where Ln stands for La or Nd, M stands for Al or Ga) are studied. Solid solutions with the rhombic perovskite structure are shown to be formed with increasing molar concentration of LnMO3 up to ∼35% (for Ln–Nd, M–Al) or ∼40% (for Ln–La, M–Ga). Further increase of the neodymium aluminate or lanthanum gallate molar content in the solid solution up to 70% leads to formation of solid solutions with the tetragonal perovskite structure. A family of promising ceramics for application in the microwave technology with dielectric permittivity lying within the range from 43 to 48, the dielectric permittivity temperature coefficient being near to zero, and heightened quality factor (Q·f ⩾40,000 GHz) are obtained.