Refinement of magnetic domains in FeTbGe2O7

Antiferromagnetic polycrystalline FeTbGe2O7 compound presents an ordered magnetic phase when its temperature decreases below the N´eel temperature TN = 42 K. By mean of Rietveld refinement of collected neutron diffraction data, the broadened part of the magnetic peaks was modeled in order to analyze...

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Bibliographic Details
Authors: I. Rosales, C. Thions-Renero, E. Orozco, M. T. Fernández-Díaz, L. Bucio
Format: article
Status:Published version
Publication Date:2015
Country:México
Institution:Universidad Nacional Autónoma de México
Repository:Redalyc-UNAM
OAI Identifier:oai:redalyc.org:57042691005
Online Access:https://www.redalyc.org/articulo.oa?id=57042691005
Access Level:Open access
Keyword:Física, Astronomía y Matemáticas
nanophase
Thortveitite
antiferromagnetic
neutron diffraction
Description
Summary:Antiferromagnetic polycrystalline FeTbGe2O7 compound presents an ordered magnetic phase when its temperature decreases below the N´eel temperature TN = 42 K. By mean of Rietveld refinement of collected neutron diffraction data, the broadened part of the magnetic peaks was modeled in order to analyze the effect of average size of magnetic domains on the evolution of magnetic structure with temperature. The rise of the magnetic structure was found to be sensitive to the shortening of distances along the b-axis between the magnetic atoms located in the bc-sheets of the layered structure. When the magnetic structure is generated, chains along the b-axis of Tb3+-Tb3+ atoms are antiferromagnetically coupled. At the same time, ferromagnetic coupling along the c-axis between Tb3+-Fe3+ atoms located in contiguous chains, couples all the chains along a sheet in the layered structure. The three-dimensional magnetic structure is reached by the ferromagnetic coupling between the set of sheets parallel to bc in the layered structure. A correlation between the size of the magnetic domain and the reach of the saturation value for the magnetic moment for Fe3+ is suggested. The magnetic reflections appear below 42 K and were modelled independently from those reflections coming from the crystal structure ignoring the effect of magnetostriction.