Study of Magnetothermal Properties of Strontium Doped Lanthanum Manganite Nanoparticles for Hyperthermia Applications

Magnetic nanoparticles of strontium doped lanthanum manganite (LSMO) have been synthesized with Sr concentration x = 0.20 and 0.27 using the citrate gel technique. Magnetic and magnetothermal properties have been investigated with the objective of determining their specific absorption rates (SAR´s) and comparing them with those obtained using the linear response theory. Adiabatic magnetothermia measurements were carried out in an RF magnetic field of 800 A/m and 214 kHz. Both magnetic and thermomagnetic behaviors of the LSMO nanoparticles are observed to be governed by the strontium content of the samples. The specific absorption rate has been determined using experimental data and good quantitative agreement has been observed between experimentally determined and theoretically derived values. Zero-field-cooled thermal demagnetization measurements were used to obtain the Curie temperature T_C, which was found to be 320 K for x = 0.20 and 350 K for x = 0.27. The suitability of these materials for magnetic hyperthermia and self-controlled hyperthermia applications has been demonstrated.