0447891 - FZÚ 2016 RIV NL eng J - Journal Article
Veverka, Pavel - Kaman, Ondřej - Kačenka, Michal - Herynek, V. - Veverka, Miroslav - Šantavá, Eva - Lukeš, I. - Jirák, Zdeněk
Magnetic La_1-xSr_xMnO₃ nanoparticles as contrast agents for MRI: the parameters affecting 1H transverse relaxation.
Journal of Nanoparticle Research. Roč. 17, č. 1 (2015), s. 1-11. ISSN 1388-0764. E-ISSN 1572-896X
R&D Projects: GA MPO FR-TI3/521; GA ČR(CZ) GAP108/11/0807
Institutional support: RVO:68378271
Keywords : manganese perovskites * manganite * magnetic nanoparticles * magnetic resonance imaging * relaxivity * core–shell particles
Subject RIV: BM - Solid Matter Physics ; Magnetism
Impact factor: 2.101, year: 2015

Magnetic nanoparticles of the La1-xSrxMnO3 perovskite phase (x = 0.20–0.45) were synthesized by a sol–gel method followed by thermal and mechanical treatments. The particles were coated with a uniform silica shell. Relaxometry measurements were focused primarily on colloids using magnetic cores of the same size (dXRD = 20 nm) and different compositions, and coated with a shell measuring approximately 20 nm in thickness. The exceedingly high transverse relaxivities [r2(20 ° C) = 290–430 s-1 mmol-1L at B0 = 0.5 T] of the samples exhibited pronounced temperature dependence and correlated very well with the magnetic data. Additional samples differing in the size of the cores and silica shell thickness were prepared as well to analyze the effect of the particles on 1H transverse relaxation. The results suggest that the dominant regime of transverse relaxation is the static dephasing regime.
Permanent Link: http://hdl.handle.net/11104/0249637