Speaker
Description
The transition metal oxides, with perovskite structure, have been largely studied because these
materials exhibit strong coupling between orbital, electronic, spin and lattice degrees of
freedom. The atomic substitution at the dodecahedral sites in stoichiometric compounds has
been extensively studied and recently, interest has turned on to the effect of the substitution at
the octahedral sites, where the experimental studies have been mainly focused on the
magnetic behaviour, and few on the multiferroic properties. In our paper we focus on
construction of structural and magnetic phase diagrams of RMn 1-x Fe x O 3 system with
perovskite crystal structure (R = Nd, Pr, Tb and Dy). Our study was performed on single
crystals prepared by optical floating zone method. We studied creation of the substitutional
solid solutions in whole concentration range, evolution of Jahn-Teller (JT) effect and orbital
ordering with substitution at the octahedral sites with non-active JT ion Fe 3+ . Construction of
magnetic phase diagrams was undertaken with particular emphasis to determination of
magnetic structure by means of magnetization, heat capacity and neutron diffraction
measurements. We paid special attention to tuning of magneto-electric (ME) coupling in
multiferroic compounds (RMnO3, R = Tb, Dy) with magnetically induced ferroelectricity by
low concentration doping with Fe.
