Effects of Nd₂O₃ on the microwave dielectric properties of BiNbO₄ ceramics

Abstract

Effects of Nd substitution with Bi on the microwave dielectric properties of BiNbO4 were studied. Bi1−xNdxNbO4 ceramics sintered at 920–980 °C consisted of orthorhombic and triclinic phases. The amount of triclinic phase increased with the increase in the Nd content, x, and sintering temperature. The apparent density and the dielectric constant decreased with the Nd content, but increased with sintering temperature, reached the peak values at 960 °C and then rapidly decreased. The Q × f0 value was between 11,000 and 13,000 GHz over all sintering temperatures for x < 0.05, but for x ≥ 0.05 it reached the peak value at 950 °C and then rapidly decreased. The temperature coefficient of resonance frequency increased in the positive direction with the Nd content and showed the minimum value of −1.82 ppm/°C for x = 0.025 sintered at 940 °C. However, it rapidly increased in the negative direction for sintering temperature over 960 °C.

Preparation of CuNb2O6 nanocrystalline powders by sol–gel method

“…These phenomena can be explained by the effects of pH values on the stable of sol-gel. In general, the stable citrate sol-gel can be easily formed because that C 3 H 5 O(COO) 3 −3 is the mainly existence formation of citrate in solution if the pH value is neutral.…”

“…In multilayer structures, dielectrics with low sintering temperature are needed as they are co-fired with low loss conductors and low melting-point electrodes made from metals such as copper and silver [3]. More recently, the binary niobate compounds with general formula MNb 2 O 6 (where M = Mg, Zn, Co, Ni, Cu, Mn and Ca etc.)…”

Dielectric and Magnetic Properties of Cr3+, Mn2+ & Fe3+ Doped BiNbO4 Ceramic Powders

“…In order to lower τ f values several researchers have attempted to modify the microwave dielectric properties of BiNbO 4 ceramics using different chemical compositions. (Bi 1-x Nd x ) NbO 4 compositions are developed by Choi et al [3] whereas Bi (Nb 1-x Ta x )O 4 compositions have been developed by Weng et al [4]. Both compositions have high (Q x f) values and low τ f values.…”

Effects of ZnO–xV2O5 substitution on the microstructure and microwave dielectric properties of ZnNb2O6 ceramics

“…Therefore, the development of low-temperature co-fired ceramics (LTCC) have been stimulated by the benefits offered for the fabrication of miniature multilayer devices involving the co-firing of dielectric and highly conductive metal, such as silver and copper [1,2]. In addition, investigations on microwave dielectric ceramics with high quality factors have become an important research trend due to their higher applied frequencies, especially in satellite communications.…”