Seminar of International Laboratory of High Magnetic Fields and Low Temperatures PAS
ul. Gajowicka 95, sala seminaryjna (nowy budynek, II piętro)
1. Direct and inverse magnetoelectric effects in the borate khantite-type family single crystals
2. Tuning the interbilayer coupling in (La1-yNdy)1.4Sr1.6Mn2O7:“chemical pressure” and rare-earth magnetism
Andrey Dubrovskiy1, Kirill Shaykhutdinov2
Kirensky Institute of Physics, RAN, Krasnoyarsk, Russia
Direct and inverse magnetoelectric effects in the borate khantite-type family single crystals
The direct (MEH-) and inverse (MEE-) magnetoelectric effects in the RM3(BO3)4 single crystals are studied, where R is a rare-earth ion or Y and M is an Al, Fe, Ga, Sc, or Cr ion. It was found the magnetoelectric effect can exist in crystals without magnetic order or spontaneous polarization. It was shown that the phenomena investigated are due to magnetostriction or magnetoelastic effect. The results obtained are explained within a proposed qualitative microscopic model, based on interplay of configuration of 4f- electron subshell of the rare-earth element and applied magnetic or electric field.
Tuning the interbilayer coupling in (La1-yNdy)1.4Sr1.6Mn2O7: “chemical pressure” and rare-earth magnetism
The aim of the study is to establish the mechanisms responsible for interbilayer coupling in bilayred manganites La2-xSr1+xMn2O7 and search for way to its controlled tuning. We synthesized the series of high-quality single crystals of bilayered manganites with formula La2-xSr1+xMn2O7 using the optical floating-zone technique. In this series we use the isovalent substitution in each of cation sublattices (La, Sr, Mn) which gives the possibility of selective influence on the parameters of interbilayered coupling at the fixed value of electron doping in Mn-O planes. Elucidation of the mechanisms and finding ways to influence the interplanar exchange in layered manganites allow to create materials with the desired parameters of the magnetic ordering, and, accordingly, the required parameters insulator-metal transition, the interplanar conductivity and magnetoresistance.
