Magnetic and Cytotoxicity Properties of La1−xSr x MnO3(0 ≤ x ≤ 0.5) Nanoparticles Prepared by a Simple Thermal Hydro-Decomposition

Sujittra Daengsakul,Chunpen Thomas,Santi Maensiri,Ian Thomas,Sineenat Siri,Charusporn Mongkolkachit,Vittaya Amornkitbamrung

doi:10.1007/s11671-009-9322-x

Abstract

This study reports the magnetic and cytotoxicity properties of magnetic nanoparticles of La1−xSrxMnO3(LSMO) withx = 0, 0.1, 0.2, 0.3, 0.4, and 0.5 by a simple thermal decomposition method by using acetate salts of La, Sr, and Mn as starting materials in aqueous solution. To obtain the LSMO nanoparticles, thermal decomposition of the precursor was carried out at the temperatures of 600, 700, 800, and 900 °C for 6 h. The synthesized LSMO nanoparticles were characterized by XRD, FT-IR, TEM, and SEM. Structural characterization shows that the prepared particles consist of two phases of LaMnO3(LMO) and LSMO with crystallite sizes ranging from 20 nm to 87 nm. All the prepared samples have a perovskite structure with transformation from cubic to rhombohedral at thermal decomposition temperature higher than 900 °C in LSMO samples ofx ≤ 0.3. Basic magnetic characteristics such as saturated magnetization (MS) and coercive field (HC) were evaluated by vibrating sample magnetometry at room temperature (20 °C). The samples show paramagnetic behavior for all the samples withx = 0 or LMO, and a superparamagnetic behavior for the other samples havingMSvalues of ~20–47 emu/g and theHCvalues of ~10–40 Oe, depending on the crystallite size and thermal decomposition temperature. Cytotoxicity of the synthesized LSMO nanoparticles was also evaluated with NIH 3T3 cells and the result shows that the synthesized nanoparticles were not toxic to the cells as determined from cell viability in response to the liquid extract of LSMO nanoparticles.

Highlights

The earlier formation of perovskite phase when there was a small doping of Sr (x \ 0.3) into the LMO structure compared with an undoped sample (x = 0) at 600 °C indicates that Sr substitution for La can help stabilize the oxide phase at lower temperature
For the samples annealed at higher temperatures (Fig. 1b–d), the peaks due to La1-xSrx MnO3 (LSMO) perovskite phase show stronger and sharper profiles resulting from the continuation of crystallization process and gradual grain growth [8]
LSMO nanoparticles with 0 B x B 0.5 have been synthesized by a simple thermal decomposition method using acetate salts in DI water

Summary

Introduction

Magnetic nanoparticles of La1-xSrxMnO3 (LSMO) with x = 0, 0.1, 0.2, 0.3, 0.4, 0.5 were prepared via the thermal hydro-decomposition method. For LSMO samples prepared at 600 °C (Fig. 1a), the perovskite structures are seen to be dominant in the samples with 0.1 B x B 0.3 while the others show many impurity phases such as La2O3, La2CO3OH, La(OH)3, and SrCO3.

Results

Conclusion