Synthesis and role of Nd and Sm on the microwave dielectric properties of BaNd2(1 − x)Sm2xTi5O14 dielectric resonator

Microstructural characteristics and microwave dielectric properties of Ba[Mg1/3(Nbx/4Ta(4−x)/4)2/3]O3 ceramics

“…9(a) indicated that the substitution of lower atomic number Nb can results in the increase of relative permittivity. In the previous research of BaNd 2(1−x) Sm 2x Ti 5 O 14 microwave dielectric ceramics [27], the substitution of lower atomic number Nd atom also resulted in an elevated value of the dielectric constant. Higher electronic polarizability will cause higher values of ε r as Nd occupies a site which will enhance the dielectric response of the system for a small increase in the electronic polarizability of the ion occupying the site.…”

Pseudo-Tungsten Bronze-Type Dielectric Materials

“…Several authors studied [3,5,10,11,13,16,19,21,29,41,57,56,[66][67][68][69][70][71][72][73][74][75][76][77][78][79][80][81][82][83][84] the dielectric properties of Ba 6-3x Ln 8 þ 2x Ti 18 O 54 ceramics for different values of x and Ln = La, Pr, Sm, Nd, Eu, Gd and are given in Table 5.3. A study of Table 5.3 shows that the ceramics based on Eu, Sm and Nd have high quality factors (Qf) up to 14 000 GHz.…”

“…It may be noted that Negas and Davies[28] reported a high Qf value of 14 000 GHz for the Eu-based ceramics. In the case of Yb having the smallest ionic radius, the Qf values deteriorated at y = 1 because the Yb ions substitute into octahedral or triangular C sites.Several authors[71,72,75,79,127] succeeded in tuning the f by partially substituting Sm by Nd. Ohsato et al[71] studied the effect of substitution of La and Nd for Sm in Ba 6-3x Sm 8 þ 2x Ti 18 O 54 (x = 0.6).…”

Microwave Dielectric Properties of SrO–2CeO2–nTiO2(n=4 and 5) Ceramics

“…Among these, BaO–RE 2 O 3 –TiO 2 [RE=Pr, Nd, Sm] have been identified as a potential material system to suit applications in the L and S band frequency for miniaturized circuits 4,5 . These tungsten bronze‐type ceramics possess a high ɛ r (70–90), a reasonably good quality factor, and a small temperature coefficient of dielectric constant (τ f ), which can be tuned with respect to rare earth substitution 6,7 . But studies have shown that it is extremely difficult to obtain a single phase of the above material and secondary phases also account for the microwave dielectric properties; thus, a careful preparation of the system is essential for its reproducibility 8,9 …”

“…4,5 These tungsten bronze-type ceramics possess a high e r (70-90), a reasonably good quality factor, and a small temperature coefficient of dielectric constant (t f ), which can be tuned with respect to rare earth substitution. 6,7 But studies have shown that it is extremely difficult to obtain a single phase of the above material and secondary phases also account for the microwave dielectric properties; thus, a careful preparation of the system is essential for its reproducibility. 8,9 Although BaO-RE 2 O 3 -TiO 2 systems are studied in detail, only very few reports are available on the structure and microwave dielectric properties of ceriumoxide-based compositions.…”