Lanthanum manganese perovskite nanoparticles as possible in vivo mediators for magnetic hyperthermia

Abstract

Manganese perovskite La 0.75Sr 0.25MnO 3 nanoparticles of the crystallite size 20–180 nm were prepared starting from citrate gel precursor by annealing in the range of 570–900 °C. It is shown that the decrease of the crystallite size leads to a gradual decrease of the magnetization and Curie temperature. The observed behaviour is a consequence of a non-collinear spin arrangement at the surface layer of crystallites, estimated to be of ∼5 nm. Magnetic heating experiments were carried out with an aqueous stable suspension of a selected sample ( M 1 T = 42 emu / g , T c = 352 K ) under an alternating field of H max = 88 mT , ν = 108 kHz . The yielded values of specific absorption rate (SAR) were found to be larger than 500 W/g Mn at 27 °C and 350 W/g Mn at 37 °C.