Article ID Journal Published Year Pages File Type
1803133 Journal of Magnetism and Magnetic Materials 2006 18 Pages PDF
Abstract

We present the temperature phase diagram of the compound DyFe4Ge2 determined from high-quality powder XRPD for the entire magnetically ordered regime. DyFe4Ge2 undergoes at TNTN, Tc=55K a simultaneous structural and magnetic transition of second-order P42/mnm  , TNTN, Tc=55K→Cmmm, followed by two subsequent isostructural first-order magnetic transitions at Tic2=45K and Tic1=28K. The structural transition at TNTN, TcTc is characterised by strong changes of the a/ba/b ratio and of the shear strain while the Tic1=28K transition is related to a lattice expansion along cc on cooling. Minor Fe parameter shifts and deformations (torsion angle and out-of plane Fe–Fe distances) of the Fe tetrahedra were found to accompany the two magnetic transitions. Using the XRPD instrumental resolution and modelling the anisotropic micro-strain enabled us to refine the observed anisotropic peak broadening associated with the presence of micro-structure effects. The maximum strain experienced by the crystal lattice during a sequence of subtle magnetic transitions was observed in the intermediate temperature interval Tic1=28K-Tic2=45K of incommensurate magnetic phases.

Related Topics
Physical Sciences and Engineering Physics and Astronomy Condensed Matter Physics
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