Dielectric Materials for Wireless Communication

CHAPTER FIVE

PSEUDO-TUNGSTEN BRONZE-TYPE DIELECTRIC MATERIALS

5.1 INTRODUCTION

In 1968 Bolton [1] made a systematic study of the TiO₂-rich region of BaO–Nd₂O₃–TiO₂ ternary system. Among various binary phases, he found two unknown ternary compounds, which had high relative permittivity and low temperature coefficient of relative permittivity. Mudroliubova et al. in 1977 [2] reported the barium rare earth titanate materials in a Russian patent. Later Kolar et al. [3–5] reported the dielectric properties of the ternary phases BaNd₂Ti₃O₁₀ (BaO–Ln₂O₃–3TiO₂; 1:1:3; Ln = lanthanide) and BaNd₂Ti₅O₁₄ (BaO–Ln₂O₃–5TiO₂; 1:1:5). During 1980–1981 Razgon et al. [6] and Gens et al. [7] reported the BaNd₂Ti₄O₁₂ (BaO–Nd₂O₃–4TiO₂; 1:1:4) composition. Figure ...