Silica encapsulated manganese perovskite nanoparticles for magnetically induced hyperthermia without the risk of overheating

O. Kaman (1, 2) , Emil Pollert (1) , P. Veverka (1) , M. Veverka (1) , E. Hadova (1) , Karel Knizek (1) , Miroslav Maryško (1) , Petr Kašpar (3) , M. Klementova (4) , V. Grünwaldová (5) , Sébastien Vasseur (6) , Romain Epherre (6) , Stéphane Mornet (6) , Graziella Goglio (6) , Etienne Duguet (6)

1 Institute of Physics
2 Department of Inorganic Chemistry
3 FEL CTU - Faculty of Electrical Engineering [Prague]
4 Institute of Inorganic Chemistry
5 Zentiva a.s.
6 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux

Nanoparticles of manganese perovskite of the composition La_0.75Sr_0.25MnO₃ uniformly coated with silica were prepared by encapsulation of the magnetic cores (mean crystallite size 24 nm) using tetraethoxysilane followed by fractionation. The resulting hybrid particles form a stable suspension in an aqueous environment at physiological pH and possess a narrow hydrodynamic size distribution. Both calorimetric heating experiments and direct measurements of hysteresis loops in the alternating field revealed high specific power losses, further enhanced by the encapsulation procedure in the case of the coated particles. The corresponding results are discussed on the basis of complex characterization of the particles and especially detailed magnetic measurements. Moreover, the Curie temperature (335 K) of the selected magnetic cores resolves the risk of local overheating during hyperthermia treatment.

Keywords: Manganese; Silica; Nanoparticles; Magnetism; Hyperthermia; Encapsulation; Perovskite

Domains: Material chemistry

O. Kaman, Emil Pollert, P. Veverka, M. Veverka, E. Hadova, et al.. Silica encapsulated manganese perovskite nanoparticles for magnetically induced hyperthermia without the risk of overheating. Nanotechnology, 2009, 20 (27), 275610 (7 p.). ⟨10.1088/0957-4484/20/27/275610⟩. ⟨hal-00403014⟩