Crystalline Structure and Dielectric Properties of Li 1+ x−y Nb 1− x −3 y Ti x +4 y O 3 M ‐Phase Solid Solutions

The structure and dielectric properties of the so‐called M ‐phase solid solutions in the Li 2 O–Nb 2 O 5 –TiO 2 system have been investigated. Detailed studies of the lattice parameters of these phases agree well with structure models based on intergrowths of LiNbO 3 slabs with a titanium‐rich corundum‐type layer. The relative permittivity ranges from ∼80 to ∼55; microwave quality factors increase with the titanium content, reaching values of Q × f = 9000 at 6 GHz. The temperature coefficient of the resonant frequency changes sign within the solid solution region, thus permitting tunability to a zero value. All the compositions can be sintered to high density at temperatures ≤1100°C.