Magnetic properties of rare-earth-doped La.sub.0.7./sub.Sr.sub.0.3./sub.MnO.sub.3./sub.

0473949 - FZÚ 2018 RIV GB eng J - Článek v odborném periodiku
Veverka, Pavel - Kaman, Ondřej - Knížek, Karel - Novák, Pavel - Maryško, Miroslav - Jirák, Zdeněk
Magnetic properties of rare-earth-doped La_0.7Sr_0.3MnO₃.
Journal of Physics-Condensed Matter. Roč. 29, č. 3 (2017), 1-9, č. článku 035803. ISSN 0953-8984. E-ISSN 1361-648X
Grant CEP: GA ČR GA15-10088S
Institucionální podpora: RVO:68378271
Klíčová slova: crystal field splitting * Tb³⁺ electronic levels * ab initio calculations * perovskite manganite * bulk versus nanoparticles
Obor OECD: Condensed matter physics (including formerly solid state physics, supercond.)
Impakt faktor: 2.617, rok: 2017

Rare-earth-doped ferromagnetic manganites La0.63RE0.07Sr0.30MnO3 (RE = Gd, Tb, Dy, and Ho) are synthesized in the form of sintered ceramics and nanocrystalline phases with the mean size of crystallites approximate to 30 nm. The electronic states of the dopants are investigated by SQUID magnetometry and theoretically interpreted based on the calculations of the crystal field splitting of rare-earth energy levels. The samples show the orthorhombic perovskite structure of Ibmm symmetry, with a complete FM order of Mn spins in bulk and reduced order in nanoparticles. Non-zero moments are also detected at the perovskite A sites, which can be attributed to magnetic polarization of the rare-earth dopants. The measurements in external field up to 70 kOe show a standard Curie-type contribution of the spin-only moments of Gd3+ ions, whereas Kramers ions Dy3+ and non-Kramers ions Ho3+ contribute by Ising moments due to their doublet ground states. The behaviour of non-Kramers ions Tb3+ is anomalous, pointing to singlet ground state with giant Van Vleck paramagnetism.
Trvalý link: http://hdl.handle.net/11104/0271047