New high Q microwave dielectric ceramics with rock salt structures: (1 − x)Li 2TiO 3 + xMgO system (0 ≤ x ≤ 0.5)

Abstract

The structural evolution and microwave dielectric properties of (1 − x)Li 2TiO 3 + xMgO system (0 ≤ x ≤ 0.5) have been investigated in this paper. The ordering degree decreased with the increase of MgO content. The microcracks and cleavage on (0 0 1) due to the weak Li–O bonds disappeared with the increase of MgO content. The dielectric constant and temperature coefficient of resonant frequency decreased with the increase of MgO content. The Q × f value increased with x up to x = 0.2 and then decreases with the further increase of x. An excellent combined microwave dielectric properties could be obtained when x = 0.24, ɛ r = 19.2, Q × f = 106,226 GHz and τ f = 3.56 ppm/°C.