Influence of Molar Ratio of Citric Acid to Metal Ions on Structure, Microstructure and Electrical Transport Properties on Nanosized La_0.85Na_0.15MnO₃

Abstract:

In this paper, nanosized La_0.85Na_0.15MnO₃ (LNMO) has been synthesized via sol-gel method by involving two major steps, first the complexation of citric acid (CA) with metal ions (MI) and second the polyesterification between CA and ethylene glycol (EG). The effect of molar ratio CA:MI varying from 2-4 on structure, microstructure and electrical transport properties of LNMO have been investigated by constant the amount of EG. All samples show single perovskite phase with hexagonal structure and space group R3c after sintering at 800°C for 10h. Sample of molar ratio 2.5 is observed to possess smallest grain sizes which yield high resistivity value compared with others, is suggested to originate from the increase of tunneling barriers (grain boundaries). The large low field magnetoresistance (LFMR) of about ~ -16% at 0.1T and low temperature confirmed the important role of grain boundaries in the nanosized LNMO.

• Periodical: Advanced Materials Research (Volume 1107)
• Pages: 261-266
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.1107.261
• Online since: June 2015
• Authors: Lim Kean Pah*, Kuen Hou Cheong, Abdul Halim Shaari, Mansor Hashim, Albert Han Ming Gan, Hui Wei Chin, Siau Wei Ng
• Keywords: Citric Acid (CA), Electrical Transport, Metal Ions, Molar Ratio, Nanosized, Sol-Gel

References

[1] A. P. Ramirez, Colossal magnetoresistance, J. Phys.: Condens. Matter 9 (1997) 8171.

[2] P. K. Siwach, H. K. Singh, and O. N. Srivastava, Low field magnetotransport in manganites, J. Phys.: Condens. Matter 20 (2008) 273201.

DOI: 10.1088/0953-8984/20/27/273201

[3] J. M. Daughton, GMR applications, J. Magn. Magn. Mater. 192 (1999) 334.

[4] A. M. Haghiri-Gosnet and J. P. Renard, CMR manganites: Physics, thin films and devices, J. Phys. D: Appl. Phys. 36 (2003) R127.

DOI: 10.1088/0022-3727/36/8/201

[5] L. M. Rodriguez-Martinez and J. P. Attfield, Structural effects of cation size variance in magnetoresistive manganese oxide perovskite, Chem. Matter. 11 (1999) 1504.

DOI: 10.1021/cm980759y

[6] P. Kameli, H. Salamati, and A. Aezami, Influence of grain size on magnetic and transport properties of polycrystalline La0. 8Sr0. 2MnO3 manganites, J. Alloys Compounds 450 (2008) 7.

DOI: 10.1016/j.jallcom.2006.10.078

[7] K. Y. Pan, S. A. Halim, K. P. Lim, W. M. W. Y. Daud, S. K. Chen and M. Navasery, Microstructure, electrical and magnetic properties of polycrystalline La0. 85K0. 15MnO3 manganites prepared by different synthesis routes, J. Mater Sci: Mater Electron 24 (2013).

DOI: 10.1007/s10854-012-1025-x

[8] P. Dey and T. K. Nath, Enhanced grain surface effect on the temperature-dependent behavior of spin-polarized tunneling magnetoresistance of nanometeric manganites, Appl. Phys. Lett. 87 (2005) 162501.

DOI: 10.1063/1.2089179

[9] T. Zhu, B. G. Shen, J. R. Sun, H. W. Zhao, and W. S. Zhan, Surface spin-glass behavior in La2/3Sr1/3MnO3 nanoparticles, Appl. Phys. Lett. 78 (2001) 3863.

DOI: 10.1063/1.1379597

[10] M. Kakihana, Sol-gel preparation of high temperature superconducting oxides, J. Sol-Gel Sci. Technol. 6 (1996) 7.

DOI: 10.1007/bf00402588

[11] L. D. Conceicao, N. F. P. Ribeiro, and M. M. V. M. Souza, Synthesis of La1-xSrxMnO3 powders by polymerizable complex method: Evaluation of structural, morphological, and electrical properties, Ceramic International 37 (2011) 2229.

DOI: 10.1016/j.ceramint.2011.03.069