Characteristics of La_0.7Sr_0.3MnO₃ Films Modified by Aluminum Ions Implantation and Post-Implantation Annealing

Shaoqun Jiang^1*, Gang Wang¹, Xinxin Ma², Xinxin Ma², Guangze Tang²

¹College of Mechanics and Materials, Hohai University, Nanjing, China.
²School of Materials Science and Engineering, Harbin Institute of Technology, Harbin, China.

DOI: 10.4236/msce.2015.31004                

Abstract

The magnetron sputtered La_0.7Sr_0.3MnO₃ films were implanted with different doses (5 ′ 10¹⁵ ions×cm?2 and 5 ′ 10¹⁶ ions×cm^-2) of Al ions at different negative pulsed voltages (30 kV and 50 kV) by plasma based ion implantation and then annealed at 973 K for 1 h in air. The microstructure, surface morphologies, surface roughness, metal-insulator transition and room temperature emittance properties of the post-implantation annealed films were investigated and compared with those of the La_0.7Sr_0.3MnO₃ film annealed at 973 K for 1 h in air. The results indicate that the post- implantation annealed films show single perovskite phase and obvious (100) preferred orientation growth. The Mn-O bond length, surface roughness and metal-insulator transition temperature (TMI) of the films can be effectively adjusted by changing implantation voltage or implantation dose of Al ions. However, the change of implantation parameters just has a small effect on room temperature emittance of the films. Compared with the annealed film, the post-implantation annealed films have shorter Mn-O bond length and lower room temperature emittance. The TMI of the films implanted at low voltage is lower than that of the annealed film, which mainly results from the degradation of oxidization during annealing process and the part displacement of Mn³⁺-O²⁺- Mn⁴⁺ double exchange channels by Al³⁺-O^2?-Mn⁴⁺. The post-implanted annealed film implanted at 50 kV/5 ′ 10¹⁶ ions×cm^-2 has a higher TMI than the annealed film, which is 247 K. The increase of TMI of the film implanted with high dose of Al ions at high voltage can be attributed to the improvement of microstructure.

Keywords

La_0.7Sr_0.3MnO₃ Film, Plasma Based Ion Implantation, Annealing; Metal-Insulator Transition, Emittance

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	Tang, G.C., Yu, Y., Chen, W. and Cao, Y.Z. (2008) Thermochromic Properties of Manganese Oxides La1-xAxMnO3 (A=Ca, Ba). Materials Letters, 62, 2914-2916. http://dx.doi.org/10.1016/j.matlet.2008.01.074
[2]	Wu, C.H., Qiu, J.W., Wang, J.B., Xu, M. and Wang, L.X. (2010) Thermochromic Property of La0.8Sr0.2MnO3 Thin- Film Material Sputtered on Quartz Glass. Journal of Alloys and Compounds, 506, L22-L24. http://dx.doi.org/10.1016/j.jallcom.2010.07.112
[3]	Shimakawa, Y., Yoshitake, T., Kubo, Y., Machida, T., Shinagawa, K., Okamoto, A., Nakamura, Y., Ochi, A., Tachikawa, S. and Ohnishi, A. (2002) A Variable-Emittance Radiator Based on a Metal-insulator Transition of (La, Sr) MnO3 Thin Films. Applied Physics Letters, 80, 4864-4866. http://dx.doi.org/10.1063/1.1489079
[4]	Shen, X.M., Xu, G.Y. and Shao, C.M. (2010) Influence of Structure on Infrared Emissivity of Lanthanum Manganites. Physica B: Condensed Matter, 405, 1090-1094. http://dx.doi.org/10.1016/j.physb.2009.11.011
[5]	Tang, G.C., Yu, Y., Cao, Y.Z. and Chen, W. (2008) The Ther-mochromic Properties of La1-xSrxMnO3 Compounds. Solar Energy Materials & Solar Cells, 92, 1298-1301. http://dx.doi.org/10.1016/j.solmat.2008.05.001
[6]	Fan, D.S., Li, Q. and Xuan, Y.M. (2011) Emissivity and Optical Properties of Thermochromic Material La0.7Ca0.3-xSrxMnO3 (0 ≤ x ≤ 0.3). International Journal of Thermophysics, 32, 2127-2138. http://dx.doi.org/10.1007/s10765-011-1062-3
[7]	Shimazaki, K., Tachikawa, S., Ohnishi, A. and Nagasaka, Y. (2001) Radiative and Optical Properties of La1-xSrxMnO3 (0 ≤ x ≤ 0.4) in the Vicinity of Metal-insulator Transition Tempera-tures from 173 to 413K. International Journal of Thermophysics, 22, 1549-1561. http://dx.doi.org/10.1023/A:1012813625195
[8]	Jiang, S.Q., Ma, X.X., Tang, G.Z., Wang, Z.H., Wang, G. and Zhou, Z.H. (2011) Microstructure and Variable Emittance Property of Annealed La-Sr-Mn-O Films. Journal of Rare Earths, 29, 83-86. http://dx.doi.org/10.1016/S1002-0721(10)60407-3
[9]	Urushibara, A., Moritomo, Y., Arima, T., Asamitsu, A., Kido, G. and Tokura, Y. (1995) Insulator-Metal Transition and Giant Magnetoresistance in La1-xSrxMnO3. Physical Review B, 51, 14103-14109. http://dx.doi.org/10.1103/PhysRevB.51.14103
[10]	Rodríguez-Martínez, L.M., Ehrenberg, H. and Attfield, J.P. (2000) Disorder Effects on Structural and Electronic Transitions in High Tolerance Factor Manganite Perovskites. Solid State Science, 2, 11-16. http://dx.doi.org/10.1016/S1293-2558(00)00117-5
[11]	Venkataiah, G., Prasad, V. and Reddy, P.V. (2007) Influence of A-Site Cation Mismatch on Structural, Magnetic and Electrical Properties of Lanthanum Manganites. Journal of Alloys and Compounds, 429, 1-9. http://dx.doi.org/10.1016/j.jallcom.2006.03.081
[12]	Tang, G.C., Yu, Y., Chen, W. and Cao, Y.Z. (2008) The Electrical Resistivity and Thermal Infrared Properties of La1?xSrxMnO3 compounds. Journal of Alloys and Compounds, 461, 486-489. http://dx.doi.org/10.1016/j.jallcom.2007.07.021
[13]	Jiang, S.Q., Tang, G.Z., Ma, X.X. and Yukimura, K. (2012) Emis-sivity of La1-xSrxMnO3/Acrylic Resin Thermal Control Coating. Rare Metal Materials and Engineering, 41, 253-255.
[14]	Jiang, S.Q., Ma, X.X., Wang, G., Tang, G.Z., Wang, Z.H. and Zhou, Z.H. (2013) Characteristics of La0.7Sr0.3MnO3-δ Films Treated by Oxygen Plasma Immersion Ion Implantation. Surface & Coatings Technology, 229, 76-79. http://dx.doi.org/10.1016/j.surfcoat.2012.04.013
[15]	Lanke, U.D. (1999) An Attempt to Replace an Anion in CMR Oxide: Nitrogen Implantation in La0.75Ca0.25MnO3. Nuclear Instruments and Methods in Physics Research B, 155, 85-90. http://dx.doi.org/10.1016/S0168-583X(99)00238-4
[16]	Jiang, S.Q., Ma, X.X., Tang, G.Z., Wang, G., Wang, Z.H. and Zhou, Z.H. (2011) Microstructure and Nano-Scratch Behaviors of La0.7Sr0.3MnO3 Films. Thin Solid Films, 519, 4880-4883. http://dx.doi.org/10.1016/j.tsf.2011.01.046
[17]	Moritomo, Y., Asamitsu, A. and Tokura, Y. (1995) Pressure Effect on the Double-Exchange Ferromagnet La1-xSrxMnO3 (0.15 ≤ x ≤ 0.5). Physical Review B, 51, 16491-16494. http://dx.doi.org/10.1103/PhysRevB.51.16491
[18]	Bathe, R., Adhi, K.P., Patil, S.I., Marest, G., Han-noyer, B. and Ogale, S.B. (2000) Silver Ion Implantation in Epitaxial La2/3Ca1/3MnO3 Thin Films: Large Temperature Coefficient of Resistance for Bolometric Applications. Applied Physics Letters, 76, 2104-2106. http://dx.doi.org/10.1063/1.126269