Mixed oxide Sm2-xMnxO3 (SMO), x = 0.0, 0.05, 0.10, 0.15 and 0.20 were synthesized by a sol-gel process. A single phase solid solution is formed up to x = 0.15 which confirmed by using X-ray diffraction, Raman spectroscopy and infrared techniques. Crystal structure and microstructure analyses were performed by Rietveld refinement. Preferential cationic distribution, over the two crystallographic sites 8b and 24d of space group Ia (3) over bar is found for doped samples but with different extent. The r.m.s. microstrain (1/2) depends on composition x in a systematic way emphasizing the preferential distribution. Magnetization measurements show that samples with x <= 0.05 have antiferromagnetic behavior, while samples with x > 0.05 exhibit a weak ferromagnetic behavior with magnetic phase transformation at 15 and 16 K for x = 0.1 and x = 0.15, respectively. (c) 2013 Elsevier Ltd. All rights reserved.