Tunable ferrimagnetic-antiferromagnetic response by the inclusion of Fe in the gadolinium-based manganite GdMnO3

In this work a study of the synthesis process, crystal structure and magnetic behavior of gadolinium manganite with Fe substitutions in Mn positions of GdMn1-xFexO3(x=0, 0.1, 0.2) is reported. The samples were synthetized by the conventional solid-state reaction method. Structural characterization of final compounds was analyzed by Rietveld refinement, which revealed its crystallization in an orthorhombic symmetry belonging to the Pbnm (No. 62) space group. Results reveal that aand ccell parameters and the unit cell volume increase, while the lattice parameter band the cell volume decrease with Fe substitution. The main effect in the structure is related to oxygen positions, i.e. in the octahedral distortions and rotations. DC susceptibility measurements, in the temperature regime between 4 K and 300 K on the application of an external field of 200 Oe, show a paramagnetic feature at high temperatures for all xstudied values, with magnetic transitions associated to a magnetic ordered state at low temperatures (21.8 K < T < 25.2 K). Meanwhile, a ferrimagnetic transition is detected for x=0.1close to T=30.7 K.In order to explain the appearance of ferrimagnetism for this configuration, a model is suggested where an imbalance in the magnetic structure of GdMnO3(type-Aantiferromagnetic) generated due to the introducing a Fe3+ion in each pair consecutive unit cells is proposed. Theeffective magnetic moment obtained agrees to the reported value for the material with x=0.0, confirming the ferrimagnetic behavior for this concentration of Fe3+in the structure.