High Q ceramics in the ACe2(MoO4)4 (A=Ba, Sr and Ca) system for LTCC applications

Structure and microwave dielectric properties of ALn4(MoO4)7 (A = Ba, Sr, Ca, Ln = La, Pr, Nd, and Sm) ceramics

“…The optimized sintering temperature, sintered density, dielectric constant, quality factor and temperature coefficient of resonant frequency of the ALn 4 (MoO 4 ) 7 (A = Ba, Sr, and Ca, Ln = La, Pr, Nd, and Sm) ceramics under study are given in Table . The BLM ceramic shows maximum density of 4.5 g/cm 3 at the sintering temperature of 710°C for 1 hour, with a dielectric constant ε r of 11.8, Q u x f of 39 300 GHz and τ f −68 ppm/ o C. SLM exhibits maximum density of 4.4 g/cm 3 at the sintering temperature of 740°C for 1 hour, with a dielectric constant of 11.7, Q u x f of 44 200 GHz and τ f −83 ppm/ o C. CLM shows maximum density of 4.2 g/cm 3 at the sintering temperature of 750°C for 1 hour, with a dielectric constant of 11.4, Q u x f of 30 200 GHz and τ f −90 ppm/ o C. Among the compositions under study CaPr 4 (MoO 4 ) 7 shows very high quality factor Q u x f of 91 000 GHz, with a dielectric constant of 10.6 and τ f −39 ppm/ o C. The ALn 4 (MoO 4 ) 7 (A = Ba, Sr, Ca, Ln = La, Pr, Nd, Sm) ceramics have dielectric constant ε r ranging from 9 to 11.8 and very high quality factor Q u x f values ranging from 30 200 to 91 000 GHz compared to the reported molybdate based LTCC compositions …”

“…Several molybdate‐based compositions have been reported as excellent ceramics for LTCC applications. Scheelite type molybdates AMoO 4 and single phase compositions with structure type BaLn 2 (MoO 4 ) 4 in the alkaline earth molybdate‐ rare‐earth molybdate phase diagram are reported as ceramics for low temperature co‐firing applications . This paper focuses on the preparation and microwave dielectric characterization of single phase compositions in the alkaline earth molybdate ‐ rare‐earth molybdate phase diagram with structural formula ALn 4 (MoO 4 ) 7 (A = Ba, Sr, and Ca, Ln = La, Pr, Nd, and Sm).…”

Microwave dielectric properties of BaY2(MoO4)4 ceramic with low sintering temperature

“…Recent studies indicated that many MoO 3 -rich systems possess high microwave dielectric properties [13][14][15][16]. Microwave dielectric properties of a new class of BaCe 2 (MoO 4 ) 4 ceramics with e r *12.3, Q 9 f *16,000-24,000 GHz and s f * -37 ppm/°C were reported for the first time by James et al [17,18]. Subsequently, the effect of ionic radii of lanthanides such as La, Nd and Sm on microwave dielectric properties of BaLn 2 (MoO 4 ) 4 ceramics with a e r *10.3-11.7, Q 9 f *20,000-45,000 GHz and s f * -76 to -45 ppm/°C was reported [19,20].…”

Microwave Dielectric Properties of a Low‐Firing Ba2BiV3O11 Ceramic

“…Recently, materials containing TeO 2 , Bi 2 O 3 , MoO 3 , P 2 O 5 , Li 2 O, and V 2 O 5 have gained considerable attention in this context . Among them, many V 2 O 5 ‐rich low‐firing ceramics show good microwave dielectric properties and some of them are suitable for the advanced substrate materials, such as R 2 V 2 O 7 (R = Ba, Sr, and Ca), (Mg 3− x Zn x )(VO 4 ) 2, LiCa 3 MgV 3 O 12, and Ba 3 MV 4 O 15 (M = Ti and Zr) .…”

“…2 Recently, materials containing TeO 2 , Bi 2 O 3 , MoO 3 , P 2 O 5 , Li 2 O, and V 2 O 5 have gained considerable attention in this context. [3][4][5][6][7][8][9] Among them, many V 2 O 5 -rich low-firing ceramics show good microwave dielectric properties and some of them are suitable for the advanced substrate materials, 10-13 such as R 2 V 2 O 7 (R = Ba, Sr, and Ca), 14 The phase composition and crystal structure were examined by X-ray diffraction (XRD) with CuK a1 radiation (Model X'Pert PRO, PANalytical, Almelo, the Netherlands). The relative densities were measured using the Archimedes method.…”