Epitaxial thin films of Li1+δMn2-δO4 (δ < 0.15) were deposited on MgAl2O4(100) and characterized. Acetate-based precursor films were deposited on thermally etched MgAl2O4 single-crystal substrates by spin-coating and subsequently annealed at 500850 &DEG; C in air. X-ray diffraction analysis indicated that Li1+δMn2-δO4 was the only crystalline product over this temperature range, and the film crystallinity increased with annealing temperature and time. The films exhibited an epitaxial relationship with the substrate of the type Li1+δMn2-δO4(100) &PAR; MgAl2O4(100) and Li1+δMn2-δO4 &LANGBRAC; 011&RANGBRAC; &PAR; MgAl2O4 &LANGBRAC; 011&RANGBRAC;. Following short (t < 10 h) anneals at or below 700&DEG; C, the surfaces of the films had a rough granular morphology. With higher annealing temperatures and/or longer times at 700&DEG; C, the surfaces of the films appeared single crystal-like, with flat (100) terraces/mesas and steps aligned along &LANGBRAC; 011&RANGBRAC;-type directions. © 2005 The Electrochemical Society.