Microwave dielectric properties of pure and Zr4+ doped lead calcium iron niobate substrates for microwave devices and antenna applications

ABSTRACT Two series of (Pb1‐xCax)(Fe0.5Nb0.5)O3 for x = 0.00, 0.20, 0.40, 0.45, 0.50, 0.55, 0.60, and (Pb0.45Ca0.55)(Fe0.5Nb0.5)1‐yZryO3 for 0.00 ≤ y ≤ 0.15 in the steps of 0.03 have been synthesized using columbite precursor method. X‐ray diffraction patterns show that all the solid solutions have tetragonal symmetry. Microwave dielectric properties of synthesized solid solutions have been investigated in X‐band (8.2–12.4 GHz). The substitution of Zr4+ ions at B‐site of (Pb0.45Ca0.55)(Fe0.5Nb0.5)1‐yZryO3 decreased the loss tangent but did not remarkably affect the relative permittivity. The temperature coefficient of relative permittivity decreased with the substitution of Ca2+ ion for Pb2+ ions at A‐site in first series. The temperature coefficient of relative permittivity further decreased with the substitution of Zr4+ ions at B‐site in second series. The reflection loss decreased but VSWR and bandwidth improved slightly with the substitution of Zr contents in second series. The present materials can be used as substrate for microwave devices and antennas applications. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2151–2155, 2015