Structural and magnetic evaluation of the CaTi1-xMx O3 (M = Dy, Ho, Gd) (x = 0.5) System

Abstract

In this work we studies and evaluates the structural and magnetic properties of CaTi1-xMxO3 system where
M = Dy, Ho, and Gd, using a substitution level of x = 0.5, in order to improve the magnetic response of synthesized materials by the solid state reaction method. For each system stoichiometric quantities of TiO2, Ho2O3, Dy2O3, Gd2O3 and CaCO3 precursors were used, which were treated at 973,15 K for 2 hours and grounded to ensure the homogeneity of compositions. The structural characterization was initiated by a modelling process provided by the SPuDS software, which allowed to evaluate the critical tolerance values of the structures under temperature conditions. The X-ray diffraction analysis and Rietveld refinement using the GSAS and EXPGUI software, revealed that all samples exhibit an orthorhombic configuration with spatial group Pnma (62). The magnetic characterization evaluates the magnetic behavior of the systems according to the magnetization curves as a function of temperature and the hysteresis curves as a function of the external field that is applied to each of the proposed systems, resulting in a paramagnetic behavior. These results demonstrate that it is necessary to complement this information to provide more effective tools in the synthesis of these materials, when determining the effect of the mass transport properties, that could affect the distribution of cation B and thus to clarify the optimal structure (with possible vacancies Of oxygen), which would lead to the formation of complex extended defects in the solids.