Crystal structures and dielectric properties of ordered double perovskites containing Mg2+ and Ta5+l

摘要

The ordered double perovskites ALaMgTaO(6) (A = Ba, Sr, Ca) and La2Mg(Mg1/3Ta2/3)O-6 have been prepared and characterized. Synchrotron X-ray powder diffraction analyses show that all four compounds exhibit a rock-salt type ordering of the B-site cations (Mg-2/Ta5+) and a random distribution of A-site cations (A(2)/La-)(3+). The space group symmetries are determined to be Fm