7th IMRMPT

Abstract

Abstract information

English title:	Structural, compositional, morphologic and magnetic features of the RCa2SbFe2O9 triple perovskite
Spanish title:	Caracter�sticas estructurales,morfol�gicas y magn�ticas de la triple perovskita RCa2SbFe2O9
English abstract:	AA'2MM'2O9 triple perovskites allow the A- and M-site cations to be varied, tripling the elemental cell in a structure in which physical properties can be tuned by the inclusion of various elements from the periodic table. When the A and A' sites are occupied by rare earth and alkaline earth cations, while M and M' by magnetic transition metals, it is possible to produce new materials with strong ferromagnetic properties at temperatures close to 300 K, making technological applications at high temperatures feasible. In this work, we report the synthesis and characterization of the triple perovskite material RCa2SbFe2O9 (La, Sm, Eu, Gd, Dy) not yet reported in the literature. Samples were produced by the solid-state reaction method from high purity precursor powders of La2O3, CaCO3, Sb2O3 and Fe3O4, which were mixed in stoichiometric proportions, according to the proposed chemical formula RCa2SbFe2O9. The crystallographic characterization was performed by X-ray diffraction (XRD) experiments using a PanAlytical X'Pert PRO-MPD equipment, which uses CuKα=1.540598 � radiation. Measurements were performed in the 2 range between 10� and 90�, with a speed of 0.02 o/s. The analysis of the XRD patterns was performed by Rietveld refinement through the GSAS code that allows to establish the crystallographic parameters, structural distortions, and microstructural defects. The surface and fracture morphology were studied by scanning electron microscopy (SEM) by a VEGA3 TESCAN equipment and the composition was analyzed by energy dispersive spectrometry (EDS). SEM micrographs evidence a strongly granular morphology and EDS spectra show that the chemical composition of the samples agrees well with the nominal values of the stoichiometric formula. Measurements of magnetization as a function of temperature and as a function of applied field were performed using a PPMS VersaLab Quantum Design SQUID, on curves of magnetic susceptibility as a function of temperature, following the ZFC (Zero Field Cooling) and FC (Field Cooled) procedures, as well as magnetization as a function of applied field. The results suggest the occurrence of magnetic ordering at temperatures close to 300 K and strong magnetic anisotropy components at low temperatures, due to the distorting effects of the crystalline structure.
Spanish abstract:	Los perovskitas triples AA'2MM'2O9 permiten variar los cationes de los sitios A y M, triplicando la celda elemental de una estructura en la que las propiedades f�sicas pueden sintonizarse mediante la inclusi�n de diversos elementos de la tabla peri�dica. Cuando los sitios A y A' est�n ocupados por cationes de tierras raras y alcalinot�rreos, mientras que M y M' por metales de transici�n magn�ticos, es posible producir nuevos materiales con fuertes propiedades ferromagn�ticas a temperaturas cercanas a 300 K, haciendo factibles aplicaciones tecnol�gicas a altas temperaturas. En este trabajo, se presenta la s�ntesis y caracterizaci�n del material de triple perovskita RCa2SbFe2O9 (La, Sm, Eu, Gd, Dy) del que no ha reportado en la literatura. Las muestras se produjeron por el m�todo de reacci�n en estado s�lido a partir de polvos precursores de alta pureza de La2O3, CaCO3, Sb2O3 y Fe3O4, que se mezclaron en proporciones estequiom�tricas, seg�n la f�rmula qu�mica propuesta RCa2SbFe2O9. La caracterizaci�n cristalogr�fica se realiz� mediante experimentos de difracci�n de rayos X (DRX) utilizando un equipo PanAlytical X'Pert PRO-MPD, que utiliza radiaci�n CuKα=1.540598 �. Las mediciones se realizaron en el rango 2 comprendido entre 10� y 90�, con una velocidad de 0.02 o/s. El an�lisis de los patrones de DRX se realiz� mediante refinamiento de Rietveld a trav�s del c�digo GSAS que permite establecer los par�metros cristalogr�ficos, distorsiones estructurales y defectos microestructurales. La morfolog�a superficial y defectos se estudi� por microscop�a electr�nica de barrido (SEM) mediante un equipo VEGA3 TESCAN y la composici�n se analiz� por espectrometr�a de energ�a dispersiva (EDS). Las micrograf�as SEM evidencian una morfolog�a fuertemente granular y los espectros EDS muestran que la composici�n qu�mica de las muestras concuerda bien con los valores nominales de la f�rmula estequiom�trica. Se realizaron mediciones de la magnetizaci�n en funci�n de la temperatura y en funci�n del campo aplicado utilizando un PPMS VersaLab Quantum Design SQUID, sobre curvas de susceptibilidad magn�tica en funci�n de la temperatura, siguiendo los procedimientos ZFC (Zero Field Cooling) y FC (Field Cooled), as� como de la magnetizaci�n en funci�n del campo aplicado. Los resultados sugieren la aparici�n de ordenamiento magn�tico a temperaturas pr�ximas a 300 K y fuertes componentes de anisotrop�a magn�tica a bajas temperaturas, debido a los efectos distorsionadores de la estructura cristalina.
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Authors

Name	Institution	Email
Diego Alejandro Rueda Cadavid	Universidad Nacional de Colombia	diaruedaca@unal.edu.co
Andr�s Hern�ndez	Universidad Nacional de Colombia	afhernandezva@unal.edu.co
Carlos Arturo Parra Vargas	Grupo F�sica de Materiales, Universidad Pedag�gica y Tecnol�gica de Colombia	carlos.parra@uptc.edu.co
Indry Milena Saavedra Gaona	Grupo F�sica de Materiales	indry.saavedra@uptc.edu.co
?David Arsenio Landinez Tellez?	Universidad Nacional de Colombia	dalandinezt@unal.edu.co
JAIRO ROA-ROJAS	Universidad Nacional de Colombia - Bogot�	jroar@unal.edu.co

Presentation

Room:	Principal Room
Date:	June 8, 2023
Hour:	09:20 - 09:40

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7^th IMRMPT
Seventh International Meeting for Researchers in Materials and Plasma Technology

Previous editions:

        1st IMRMPT 2011
        2nd IMRMPT 2013
        3rd IMRMPT 2015
        4th IMRMPT 2017
        5th IMRMPT 2019
        5+1 IMRMPT 2021

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