Investigación

 

Synthesis and magnetic characterization of LaMnO₃ nanoparticles

 

E. Hernández^a, V. Sagredo^a and G.E. Delgado^b

 

^a Laboratorio de Magnetismo, Departamento de Física, Facultad de Ciencias, Universidad de Los Andes, Mérida 5101, Venezuela.

^b Laboratorio de Cristalografía, Departamento de Química, Facultad de Ciencias, Universidad de Los Andes, Mérida 5101, Venezuela.

 

Received 26 November 2014;
accepted 30 January 2015

 

Abstract

LaMnO₃ Nanoparticles systems were prepared by the sol-gel auto-combustion method, in order to analyze the structure and magnetic behavior presented by the compound prepared following a new alternative route of synthesis. Structural characterization, morphology and crystallite size was performed by X-ray diffraction (XRD), infrared spectroscopy (IR) and electron microscopy (TEM). The XRD study together with a Rietveld analysis showed that the LaMnO₃ compound crystallized in a perovskite hexagonal structure. The IR spectra showed that the compound has tensile energy bands in the Mn-O-Mn bonds related with the octahedron MnO₆; which are attributed to a characteristic vibration of the ABO₃ perovskite. An estimated size and morphological analysis was carried out by applying the Scherrer's formula and using Transmission Electron Microscopy (TEM), revealing non-spherical shape and particle sizes between 13 nm and 18 nm. The magnetic measurements M(T) were performed by using zero-field-cooled (ZFC) and field-cooled (FC) protocols which revealed a positive Weiss temperature indicating the presence of ferromagnetic interactions with a Curie temperature, T_C = 150 K.

Keywords: Auto-combustion; curie temperature; magnetization; manganites; nanoparticles; ferromagnetism; perovskite; Sol-Gel.

 

PACS: 75.60.Ej; 75.47.Lx; 73.22.-f; 81.20.Fw

 

DESCARGAR ARTÍCULO EN FORMATO PDF

 

Acknowledgments

The authors want to acknowledge to the CDCHTA-ULA for funding the proyect C-1658-09-05-A.

The authors want to acknowledge to C. Pernechele and F. Rossi. Dipartamenti di Fisica, CNISM, Universita di Parma, A-1-43100, Italia, and IMEM-CNR Institute, 43019, Parma Italia respectively.

 

References

1. M.R. Levy, Tesis Doctoral Departamento de Materiales (Universidad de Landres, 2005).

2. Y. Romaguerra Barcelay. Tesis Doctoral en Física (Universidad de Porto 2012).

3. D. Varshney and N. Kaurav, Eur. Phys. J. B 37 (2004) 301-309.         [ Links ]

4. S. Ghosh, A.D. Sharma, R.N. Basu, and H.S. Maiti, J. Am. Ceram. Soc. 3741 (2007) 3747.         [ Links ]

5. F. Fernández. Tesis Doctoral en Química, Universidad de Santiago de Compostela, 2000.

6. E. Pérez, Seminario, Métodos de Preparación de nanopartículas (Universidad de los Andes, Mérida Venezuela, 2012).         [ Links ]

7. Z.A. Munir, J.B. Holt, J. Mater. Sci. 22 (1987) 710-714.         [ Links ]

8. E. Chinarro. E. Chinarro, B. Moreno, D. Martin, L. González, E. Villanueva, D. Guinea y J.R. Jurado, Bol. Soc. Esp. Ceram. Vol 44 (2005) 105-112.         [ Links ]

9. A. Kumar, A.S. Verma and S.R. Bhardwaj, The Open Applied Physics Journal 1 (2008) 11.         [ Links ]

10. J. Coey and S. Von Molnar, Advances in Physics 48 (1999) 167.         [ Links ]

11. K.B. LiK, X.J. Li and K.G. Zhu, J. Appl. Phys. 10 (1997) 6943.         [ Links ]

12. H. Wang, Z. Zhao, C.-mingXu and J. Liu, Catalysis Letters 102(2005) 5864.         [ Links ]

13. A. Giri, A. Makhal, B. Ghosh, A. K. Raychaudhuriand Samir Kumar Pal, Nanoscale 2 (2010) 2704-2709.         [ Links ]

14. L.G. Wade, Química Orgánica. 5 edición, (2005).         [ Links ]

15. V. Zakhvalinski, Physics of LaMnO_(3±δ) the Solid State 48 (2012) 2300.         [ Links ]

16. F. Pardo, Journal of Solid State Chemistry 146 (1999) 418-427.         [ Links ]

17. S.V. Trukhanov, Journal of Low Temperature Physics 139 (2005) 4734.         [ Links ]

18. J. Topferl and J.B. Odenough, Chemistry. Journal of Solid State 130 (1997) 117-128.         [ Links ]

19. T.I. Arbuzova, Physic Solid State 50 (2008) 1487-1494.         [ Links ]

20. K. Kamata, Mat. Res. Bull. Vol. 13 (1978) 49-54.         [ Links ]

21. N. Kamegashira, Materials Chemistry and Physics II (1984) 181-194.         [ Links ]

22. S. Roy, I.S. Dubenko, M. Khan, E.M. Condon, J. Craig, and N. Ali, Phys. Rev B 71 (2005) 024419.         [ Links ]