New high Q microwave dielectric ceramics with rock salt structures: (1−x)Li2TiO3+xMgO system (0≤x≤0.5)

Li 4 WO 5 : A temperature stable low-firing microwave dielectric ceramic with rock salt structure

“…4 shows SEM image of the fractured surface of the ceramic sintered at 890 • C. As seen, a relatively dense microstructure with some porosity was observed. A similar porous microstructure was reported in Li 2 TiO 3 ceramic [18]. The authors ascribed the porosity to the evaporation of lithium at elevated temperatures and the phase transition.…”

“…Among them, some Li-containing compounds with rock salt structure, such as Li 2 TiO 3 and Li 3 NbO 4 , were reported to exhibit a combination of low sintering temperature and excellent microwave dielectric properties [18][19][20]. For example, Li 2 TiO 3 had a permittivity of 22, Q × f value of 63,500 GHz (at 8.6 GHz), and f value of 20.3 ppm/ • C [18]. Li 3 NbO 4 could be well sintered at 930 • C with good microwave dielectric properties: r = 16.4, f = −45 ppm/ • C and Q × f = 47,179 GHz (8.7 GHz) [21].…”

“…The rock salt structure is one of the most common and well-known structure types. It is characterized by edge shared octahedrons coordinated for both cations and anions to form three-dimensional network [18]. A site can be occupied by two or three crystallographically distinct types of cations, e.g., Li 2 TiO 3 and Li 3 NbO 4 .…”

Microstructure and microwave dielectric properties of (1−y)Li3NbO4+yLi2TiO3(Li2SnO3) ceramics

“…Recently, we have investigated the microwave dielectric properties of lithium-containing oxides with rock salt structure, and obtained several high Q × f value dielectric ceramics in this system [4]. Among them, Li 2 TiO 3 in which Li layers alternated with ordered (Li, Ti) layers has the dielectric constant of 22, Q × f value of 63,500 GHz (8.6 GHz), and f value of 20 ppm/ • C. Its Q × f value was considerably improved to 106,226 GHz (8.8 GHz) by a small amount of MgO addition (24 mol%), although the ordering degree decreased with the addition of MgO [5]. The f value could be tuned to 3.6 ppm/ • C simultaneously.…”

A new microwave dielectric material LiNi0.5Ti0.5O2

“…To meet the specifications of current and future applications, improved or new microwave components based on dedicated dielectric materials are required. Varieties of microwave dielectric ceramics with high quality factor have been intensively investigated, such as ZnTa 2 O 6 , ZnTiNbTaO 8 , Li 2 (Zn 1À x A x )Ti 3 O 8 (A=Mg, Co), (1À x)Li 2 TiO 3 þ xMgO [4][5][6][7].…”