Mapping of reciprocal space of La0.30CoO2 in 3D: Analysis of superstructure diffractions and intergrowths with CO3O4

作者：Brazda Petr^*; Palatinus Lukas; Klernentova Mariana; Bursik Josef; Knizek Karel

来源：Journal of Solid State Chemistry, 2015, 227: 30-34.

DOI：10.1016/j.jssc.2015.03.016

• Thermoelectric cobaltates
• LaxCoO2
• Transmission electron microscopy
• Electron diffraction tomography
• X-ray diffraction
• Co3O4 intergrowths

We have used electron diffraction tomography and powder X-ray diffraction to elucidate the structural properties of layered cobaltate gamma-La0.30CoO2. The structure consists of hexagonal sheets of edge-sharing CoO6 octahedra interleaved by lanthanum monolayers. The La3+ cations occupy only one third of available P2 sites, forming a 2-dimensional a root 3 x a root 3 superstructure in a-b plane. The results show that there exists no order in the mutual relative shift between the neighbouring La interlayers within the a-b plane. This is manifested in the observed monotonous decrease of the diffracted intensity of the superstructure diffractions along c* in both X-ray and electron diffraction data. The observed lack of stacking order differentiates the LaxCoO2 from its Ca and Sr analogues where at least a partial stacking order of the cationic interlayers is manifested in experimental data published in literature.

• 出版日期2015-7