TY - JOUR
T1 - Domain structures in perovskite-type lanthanum magnesium titanate ceramics
AU - Kipkoech, Erick Rop
AU - Azough, Feridoon
AU - Freer, Robert
PY - 2005
Y1 - 2005
N2 - La(Mg 1/2Ti 1/2)O 3 ceramics were prepared using a conventional solid-state reaction route. X-ray diffraction analysis revealed that La(Mg 1/2Ti 1/2)O 3 possesses a distorted perovskite structure consisting of both in-phase and anti-phase tilting accompanied by anti-parallel shifting of La 3+ cation. Superlattice reflections, indicative of 1:1-type ordering of Mg 2+ and Ti 4+ cations in the octahedral sites, were observed. The crystal symmetry was deduced to be monoclinic with P2 1/n space group (No. 14). Transmission electron microscopy analysis revealed two types of twin domains, classified according to the symmetry elements relating adjacent domains. Twin domains with specific orientations, related by mirror operations along {112} and (110) planes, were identified. La(Mg 1/2Ti 1/2)O 3 exhibited a high density of dislocations that interact with the twin boundaries resulting in incoherent twin interfaces. In addition, two morphologically distinct anti-phase domains were observed resulting from (i) off-center displacement of the La 3+ cations, and (ii) 1:1 ordering of the B-site sublattice.
AB - La(Mg 1/2Ti 1/2)O 3 ceramics were prepared using a conventional solid-state reaction route. X-ray diffraction analysis revealed that La(Mg 1/2Ti 1/2)O 3 possesses a distorted perovskite structure consisting of both in-phase and anti-phase tilting accompanied by anti-parallel shifting of La 3+ cation. Superlattice reflections, indicative of 1:1-type ordering of Mg 2+ and Ti 4+ cations in the octahedral sites, were observed. The crystal symmetry was deduced to be monoclinic with P2 1/n space group (No. 14). Transmission electron microscopy analysis revealed two types of twin domains, classified according to the symmetry elements relating adjacent domains. Twin domains with specific orientations, related by mirror operations along {112} and (110) planes, were identified. La(Mg 1/2Ti 1/2)O 3 exhibited a high density of dislocations that interact with the twin boundaries resulting in incoherent twin interfaces. In addition, two morphologically distinct anti-phase domains were observed resulting from (i) off-center displacement of the La 3+ cations, and (ii) 1:1 ordering of the B-site sublattice.
U2 - 10.1111/j.1551-2916.2005.00128.x
DO - 10.1111/j.1551-2916.2005.00128.x
M3 - Article
SN - 0002-7820
VL - 88
SP - 768
EP - 772
JO - Journal of the American Ceramic Society
JF - Journal of the American Ceramic Society
IS - 3
ER -