  Variations in growth conditions associated with different deposition
techniques can greatly affect the phase stability and defect structure of
complex oxide heterostructures. We synthesized superlattices of the
paramagnetic metal LaNiO3 and the large band gap insulator LaAlO3 by atomic
layer-by-layer molecular beam epitaxy (MBE) and pulsed laser deposition (PLD)
and compared their crystallinity, microstructure as revealed by high-resolution
transmission electron microscopy images and resistivity. The MBE samples show a
higher density of stacking faults, but smoother interfaces and generally higher
electrical conductivity. Our study identifies the opportunities and challenges
of MBE and PLD growth and serves as a general guide for the choice of
deposition technique for perovskite oxides.
