The microwave dielectric properties and microstructures of (1 ¹ y) (Mg 0.95 4 Ta 2 O 9 0.7(Ca 0.8 Sr 0.2 )TiO 3 has an excellent combination of microwave dielectric properties: ¾ r ³ 29.8, Q©f ³ 226,000 GHz (at 9 GHz), and¸f ³ ¹2.38 ppm/°C sinter at 1350°C. It is proposed as a candidate material for industrial, scientific and medical band components and Global Position System antennas.

The microstructure of (Mg 0.95 Ni 0.05 ) 4 (Nb 1¹x Ta x ) 2 O 9 ceramics was analyzed using X-ray diffractometry and scanning electron microscopy. The quality factor (Q©f ) values of (Mg 0.95 Ni 0.05 ) 4 (Nb 1¹x Ta x ) 2 O 9 (x = 1) ceramics increase with increasing sintering temperature, with the maximum value obtained at 1375°C. The maximum values of electric permittivity (¾) and Q©f were 12.76 and 442,000 GHz, respectively, for (Mg 0.95 Ni 0.05 ) 4 (Nb 1¹x Ta x ) 2 O 9 (x = 1) ceramics sintered at 1375°C for 4 h. Furthermore, the temperature coefficient of resonant frequency (¸f ) measured for (Mg 0.95 Ni 0.05 ) 4 (Nb 1¹x Ta x ) 2 O 9 (x = 1) ceramics is ¹54 ppm/°C.

The prepared (Mg 1¹x

The microstructure of (Mg 0.95 Ni 0.05) 4 (Nb 1-x Ta x) 2 O 9 is analyzed using X-ray diffractometry and scanning electron microscopy. The Qxf values of (Mg 0.95 Ni 0.05) 4 (Nb 1-x Ta x) 2 O 9 increases with increasing sintering temperature; and then up to a temperature of 1375°C significantly decreased. The maximum values of the electric permititivity and the quality factor (Qxf) can be obtained 12.76 and 442,000 GHz is obtained for (Mg 0.95 Ni 0.05) 4 (Nb 1-x Ta x) 2 O 9 sintered at 1375°C for 4 h. The temperature coefficient of resonant frequency (τ f) measured for (Mg 0.95 Ni 0.05) 4 (Nb 1-x Ta x) 2 O 9 is −54 ppm/°C.