THE INFLUENCE OF METAL-ION INCLUSION ON THE MORPHOLOGY OF GIBBSITE

The microscopic growth mechanism of gibbsite is examined via crystalli zation in the presence of alkali metal ions, The morphology is found t o be hexagonal plates in the presence of sodium, but hexagonal prisms in the presence of potassium and caesium. The former morphology is ver y similar to the calculated equilibrium morphology which ignores the e ffect of the growth medium. Further calculations examining the possibl e lattice sites of the incorporated defects show that different positi ons are most stable for sodium and potassium/caesium, providing an exp lanation for the different morphology.