Nanocomposites and nanomaterials 

Effect of Ce ions on the crystallochemical properties of (La,Ce,Sr)MnO3

Timashkov I., Shlapa Yu., Belous A.
Department of Solid State Chemistry, Institution of General and Inorganic Chemistry of the NAS of Ukraine. Prospect Palladina, 32/34, Kyiv-03142, Ukraine. 
E-mail: timashkov.chem@gmail.com

Magnetic nanoparticles (NPs) are promising for wide application in medicine, for instance in hyperthermia of malignant tumors [1]. With this purpose, NPs must be able to heat up in an alternating magnetic field (AMF). At present, it is interesting to develop multifunctional NPs, which can demonstrate not only heating ability in AMF, but also have antioxidant activity (AOA). It is important because in therapy of malignant tumors can be a necessity to fight the occurred oxidative stress. From this point of view, it is interesting to create NPs based on (La,Sr)MnO3 manganite, which can controllable heat up in AMF to certain temperatures, with doped ions that are able to provide AOA. 
The aim of this study were synthesis of Ce-doped La0.7-xCexSr0.3MnO3 (x = 0 – 0.2) manganites and investigation of their crystallochemical properties.
Table I. The main parameters of NPs
Sample
Parameters	Ce_0	Ce_0.02	Ce_0.03	Ce_0.05	Ce_0.07	Ce_0.1	Ce_0.2	
Cell volume, (Å3)	355.8 	355.4	350.0	348.2	348.2	348.1	347.7	
Specific loss power, (W/g)	42	26	21	19	19	19	17	
La0.7-xCexSr0.3MnO3 NPs were synthesized by sol-gel method with further heat treatment at 800°C. According to X-ray diffraction analysis, it was established that in the range of Ce substitution in the La sublattice up to 5% at 800°C, single-phase solid solutions were formed and at Ce concentrations more than 5%, formation of an additional phase of CeO2 was observed.
It was showed that NPs heated up effectively under the action of AMF to the controlled temperatures and their heating efficiency decreased with growing Ce concentration in the sample (Table I).

1.	Zarschler K., Rocks L., Licciardello N. et al. Ultrasmall inorganic nanoparticles: State-of-the-art and perspectives for biomedical applications // Nanomed. Nanotechnol Biol. Med. – 2016. – Vol. 12. – P. 1663.