| Enhanced quality factor of CaMo1-xTexO4 ceramics by Te6+ substitution |
| Joo Hyeon Kim, Eung Soo Kim |
| Department of Advanced Materials Engineering, Kyonggi University, Suwon, Gyeonggi-do, 16227, Korea |
|
|
|
Received: July 14, 2023; Revised: October 15, 2023 Accepted: October 29, 2023. Published online: November 2, 2023. |
|
|
|
| ABSTRACT |
|
Microwave dielectric properties of CaMo1-xTexO4 (0.01≤x≤0.05) ceramics were investigated based on the crystal structure characteristics. For the specimens sintered at 900–985 °C for 2 h, a single phase of scheelite structure was confirmed up to x=0.03, and then secondary phases were observed for further substitution. With an increase in Te6+ content, the quality factor (Qf) of the sintered specimens increased up to x=0.03 (Qf=185,500 GHz) and then decreased. The amelioration in the Qf up to x=0.03 is due to the increase in the B-site bond valence of ABO4; however, the degradation of the Qf above x=0.03 could be attributed to the formation of secondary phases. With an increase in Te6+ content, the dielectric constant (K) of the specimens increased from K=10.42 to K=10.78 due to the higher polarizability of Te6+ (3.7 Å3) than that of Mo6+ (3.28 Å3). As the Te6+ content increased, the temperature coefficient of resonant frequency (TCF) decreased with an increase in oxygen bond valence. Excellent microwave dielectric properties (Qf=185,500 GHz, K=10.62, TCF = -36.53 ppm/°C) were obtained for the CaMo0.97Te0.03O4 ceramics which could be applicable to various microwave communication systems. |
| Key words:
CaMoO4 · Scheelite structure · Microwave dielectric properties · Bond characteristics |
|
PDF Links 
Full text via DOI
Download Citation 
