Zhang K, Holloway T, Pradhan J, Bahoura M, Bah R, Rakhimov R R, Pradhan A K, Prabakaran R, Ramesh G T
Center for Materials Research, Norfolk State University, 700 ParkAvenue, Norfolk, VA 23504, USA.
J Nanosci Nanotechnol. 2010 Sep;10(9):5520-6. doi: 10.1166/jnn.2010.2437.
The La(1-x)Sr(x)MnO3 (LSMO) nanoparticles have been synthesized by citric gel process followed by ball milling method. These nanoparticles demonstrated high crystalline quality. Nanoparticle size was further decreased by ball milling technique as observed by the field-emission scanning electron microscopic studies. The ball milled and silica coated LSMO nanoparticles show magnetic transition at about 370 K with a superparamagnetic properties. The ferromagnetic resonance (FMR) spectra analysis of LSMO nanoparticles shows large FMR linewidth due to the surface strain of the nanoparticles. Both magnetization and FMR studies demonstrate that the LSMO nanoparticles are highly anisotropic. The toxicity of the nanoparticles was studied for safe biomedical applications. Measurement of intracellular reactive oxygen species (ROS) and MTT assay results show that LSMO nanoparticles are relatively nontoxic and the toxicity is further reduced by SiO2 coating. These results are very important for applications in the field of biotechnology.
通过柠檬酸凝胶法并结合球磨法合成了La(1 - x)Sr(x)MnO3（LSMO）纳米颗粒。这些纳米颗粒展现出高结晶质量。通过场发射扫描电子显微镜研究观察到，采用球磨技术进一步减小了纳米颗粒的尺寸。球磨并包覆二氧化硅的LSMO纳米颗粒在约370 K时呈现磁转变，具有超顺磁特性。LSMO纳米颗粒的铁磁共振（FMR）光谱分析表明，由于纳米颗粒的表面应变，FMR线宽较大。磁化和FMR研究均表明LSMO纳米颗粒具有高度各向异性。为了安全的生物医学应用，对纳米颗粒的毒性进行了研究。细胞内活性氧（ROS）的测量和MTT分析结果表明，LSMO纳米颗粒相对无毒，并且通过SiO2包覆进一步降低了毒性。这些结果对于生物技术领域的应用非常重要。
