The effect of doping donor ions in the dielectric properties of (In 0.5 B 0.5 ) 0.1 Ti 0.9 O 2 (B--V, Nb, Ta) ceramics

With the rapid development of integrated circuits, TiO2-based colossal dielectric constant ceramics have been widely studied as a critical alternative material in MLCC (Multilayer Ceramic Capacitors). However, the preparation technique is primarily based on the traditional solid-phase reaction method. In this work, (In 0.5 V 0.5 ) 0.1 Ti 0.9 O 2 , (In 0.5 Nb 0.5 ) 0.1 Ti 0.9 O 2 , and (In 0.5 Ta 0.5 ) 0.1 Ti 0.9 O 2 (abbreviated as IVTO, INTO, and ITTO) ceramics were prepared by a sol-gel method. In comparison, Nb5+ (r = 0.64 & Aring;) and Ta5+ (r = 0.65 & Aring;) have close ionic radii, which are more susceptible to Ti4+ (r = 0.745 & Aring;) sites substitution than V 5+ of a small ionic radius (r = 0.54 & Aring;), effectively facilitating the carrier concentration. Meanwhile, the Ta5+ has another advantage in refining the ceramic grain size to further improve grain boundary resistance. The ITTO ceramics show a colossal dielectric constant of 9.3 x 104, low dielectric loss of 0.07 (1 kHz, room temperature), and stable temperature application range for X9F (-55 degrees C-200 degrees C, Delta epsilon r /epsilon 25 degrees C <= +/- 7.5 %). The dielectric mechanism is related to the internal barrier layer capacitance (IBLC) effect. Thus, this work as a novel strategy provides an effective mean for further development of future colossal dielectric constant materials.