Thermal events encountered throughout the heat treatment of praseodymium acetate, Pr(CH3COO)(3)center dot H2O, were studied in nitrogen and air atmospheres. The samples calcined at the 300-700 degrees C temperature range were characterized using XRD, IR and N-2 adsorption. Moreover, in situ electrical conductivity was employed to follow up the formation of the different decomposition intermediates. The results indicated that the anhydrous salt decomposes to the final product, PrO1.833, through the formation of the following intermediates: Pr(OH)(CH3COO)(2), PrO(CH3COO) and Pr2O2(CO3). PrO1.833 formed at 500, 600, and 700 degrees C possesses a surface area of 17, 16 and 10 m(2)/g and crystallites size of 14, 17 and 30 nm, respectively.(c) 2008 Elsevier B.V. All rights reserved.