Crystal Engineering of Nanomorphology for Complex Oxide Materials via Thermal Decomposition of Metal-Organic Frameworks. Case Study of Sodium Tantalate

Application of different solvating ligands drastically changes the composition and geometry of bimetallic sodium-tantalum pinacolates, forming insoluble and stable organic-inorganic hybrid materials through Van der Waals interactions. The loss of these neutral ligands on heating leads to contraction and densification of the structures, with formation of covalent metal organic frameworks (MOFs) as intermediates, and resulting in direction-specific cracking and formation, on further thermal decomposition, of low-dimensional nanomorphologies-wires or plates of the same oxide material, containing well-crystalline monoclinic NaTaO3 as its major component. The crystallographic features of the precursor structures permitting us to control further morphological differentiation on the transformation to oxide material are identified.