Dielectric and structural characteristics in barium lanthanum magnesium niobate

The dielectric properties and their related microstructural characteristics in solid solutions of (1 - x)Ba(Mg1/3Nb2/3)O-3 (BMN)-xLa(Mg2/3Nb1/3)O-3 (L MN) (BLMN) were investigated by measuring the relative permittivity (epsilo n(r)), Q value, and temperature coefficient of resonator frequency (tau(f)) , and by observing the microstructure using transmission electron microscop y, The trend of variation of the temperature coefficient of the dielectric permittivity (tau(epsilon)) was the same for our solid solutions as that re ported by Reaney st al, When the tolerance factor (t) was >1.01 in BLMN wit h composition x = 0 to 1,0, where the tilting of oxygen octahedra,vas not i nvolved, the components of the microstructure included a disordered and tra nsition phase as well 1:1 and 1:2 ordered phases. In the region where 1.01 < t < 0.96 with x = 0.2 to 0.7, the 1:1 order, the disorder, and the phase due to the antiphase tilting of oxygen octahedra were present. Finally, in the region where t ( 0.96 with x = 0.7 to 1,0, the microstructure of BLMN w as the same as that of the pure LMN, including the 1:1 order and the antiph ase, inphase tilting of oxygen octahedra, and the antiparallel shift of A-s ite cations.