Dielectric Characteristics of Nd(Zn_1/2Ti_1/2)O₃ Ceramics at Microwave Frequencies

Abstract

The microwave dielectric properties and the microstructures of Nd(Zn1/2Ti1/2)O3 (NZT) ceramics prepared by the conventional solid‐state route have been studied. The prepared NZT exhibited a mixture of Zn and Ti showing 1:1 order in the B‐site. The dielectric constant values (ɛr) saturated at 29.1–31.6. The quality factor (Q×f) values of 56 700–170 000 (at 8.5 GHz) can be obtained when the sintering temperatures are in the range of 1300°–1420°C. The temperature coefficient of resonant frequency τf was not sensitive to the sintering temperature. The ɛr value of 31.6, the Q×f value of 170 000 (at 8.5 GHz), and the τf value of −42 ppm/°C were obtained for NZT ceramics sintering at 1330°C for 4 h. For applications of high selective microwave ceramic resonators, filters, and antennas, NZT is proposed as a suitable material candidate.

Influence of cooling rate on the structure and microwave dielectric properties of Nd(Zn1/2Ti1/2)O3 ceramics

“…A maximum Q Â f value of 165,300 GHz was obtained for Nd(Zn 1/2 Ti 1/2 )O 3 ceramics sintered at 1360 1C for 4 h with a cooling rate of 1 1C/min. The values of Q Â f measured for all compositions are about a factor of (4-6) higher than the value reported previously by Iddles et al [14], but almost the same as those reported by Tseng et al [9]. It is well known that there are many factors such as density, secondary phase, grain size and cation ordering to influence microwave dielectric loss of a material [21].…”

“…Among these materials, Nd(Zn 1/2 Ti 1/2 ) O 3 ceramics were found to possess better microwave dielectric properties (ε r =31.6, Q Â f=170000 GHz and τ f = À 42 ppm/ o C) after sintering at 1330 1C for 4 h with a cooling rate of 10 1C/ min [9]. However, the maximum available from a reported UK patent was around 27,000 GHz, with maximum ε r of 27.5 when Nd(Zn 1/2 Ti 1/2 )O 3 ceramics were sintered at 1500 1C for 8 h [14].…”

“…Compared with the above mentioned systems, several double perovskite ceramics Ln(B 1/2 Ti 1/2 )O 3 (Ln¼ La, Nd, and Sm; B ¼ Zn, and Co) have drawn considerable attention in recent years due to their excellent microwave dielectric properties, especially ultrahigh quality factor (37,000-170,000 GHz) [8][9][10][11][12][13]. Among these materials, Nd(Zn 1/2 Ti 1/2 ) O 3 ceramics were found to possess better microwave dielectric properties (ε r =31.6, Q Â f=170000 GHz and τ f = À 42 ppm/ o C) after sintering at 1330 1C for 4 h with a cooling rate of 10 1C/ min [9].…”

Effect of ZnO additive on sintering behavior and microwave dielectric properties of 0.95MgTiO3–0.05CaTiO3 ceramics

“…As observed in Fig. 6, the τ f value varied toward A breaking point appears at 1300 • C and the variation of τ f becomes downward due to the decrease of ZnTiO 3 phase resulted from Zn evaporation as the sintering temperature rises above 1300 • C [15]. The Zn position was most likely occupied by exceeding Mg to form MgTiO 3 .…”

Crystallization behavior and microwave dielectric characteristics of ZnO-(La, Nd)2O3-B2O3-based dielectrics

“…The LTCC technology offers the possibility of the monolithic multilayer structures with buried passive components as a key development for integrated electronic components including IC packaging radar and antennas [1][2][3]. As an LTCC substrate material, dielectric ceramics have been investigated to meet the target characteristics such as low dielectric constant and high quality factor [4][5][6].…”