利用脉冲激光沉积法在SrTiO3(001)上生长了La0.8Ba0.2MnO3薄膜,我们研究了退火对其表面形貌、电学和磁学性能的影响。生长完成后,在500 mbar氧气氛中原位退火2小时可以使薄膜表面的均方根粗糙度从1.24nm减小到0.24nm。退火2小时后,薄膜的绝缘-金属相变温度增加了约100K。然而,当退火时间达到3小时,由于在晶格中掺入过量的氧,薄膜在220K以下出现其它的绝缘相。结果表明,适当的退火条件对优化脉冲激光沉积法制备的锰氧化物薄膜的表面微结构和物理性质尤为重要。 We studies the effects of annealing on the surface morphology, electrical and magnetic properties of La0.8Ba0.2MnO3 films on SrTiO3 (001) substrates grown by pulsed laser deposition. The root- mean-square roughness of the surfaces decrease significantly from 1.24 nm for as-grown films to 0.24 nm for annealed films when the films are annealed in 500 mbar oxygen for 2h. The insulator-metal phase transition temperature increases by around 100K after 2h annealing. When the annealing time rises up to 3h, however, an additional insulating phase appears below 220 K as a result of excess oxygen incorporated in the crystal lattices. Our results indicate that appropriate post-annealing conditions are necessary to optimize the surface microstructure and physical properties of manganites, especially for films prepared by pulsed laser deposition.
退火时间,锰氧化物,磁学性质,电学性质, Annealing Time Manganite Magnetic Properties Electric Properties退火处理对La0.8Ba0.2MnO3薄膜的表面形貌、电学及磁学性能的影响
This work is licensed under the Creative Commons Attribution International License (CC BY).
http://creativecommons.org/licenses/by/4.0/
1. 引言
自从Jin等人发现钙钛矿型的La-Ca-Mn-O体系中的庞磁电阻效应(CMR)以来 [1] ,对于锰氧化物La1-xAxMnO3 (A = Sr, Ba, Ca, Ce, Hf)的研究引起了研究者们广泛的关注。锰氧化物除了具有惊人的CMR效应,其自旋、电荷、轨道以及晶格等自由度之间的强烈耦合使得它们表现出有趣的磁学和电学性质,因而在未来的磁存储器和磁传感器中具有潜在的应用前景。
魏 杰,王安成,胡慧敏,刘国珍,仇 杰. 退火处理对La0.8Ba0.2MnO3薄膜的表面形貌、电学及磁学性能的影响 Effects of Annealing on the Surface Morphology, Electrical and Magnetic Properties of La0.8Ba0.2MnO3 Thin Films[J]. 应用物理, 2017, 07(04): 111-117. http://dx.doi.org/10.12677/APP.2017.74016
参考文献 (References)ReferencesJin, S., Tiefel, T.H., Mccormack, M., et al. (1994) Thousandfold Change in Resistivity in Magnetoresistive La-Ca-Mn- O Films. Science, 264, 413-415. <br>https://doi.org/10.1126/science.264.5157.413Zener, C. (1951) Interaction between the d-Shells in the Transition Metals. II. Ferromagnetic Compounds of Manganese with Perovskite Structure. Physical Review, 82, 403. <br>https://doi.org/10.1103/PhysRev.82.403Turcaud, J., Pereira, A. and Cohen, L. (2015) Quantifying the Deleterious Role of Strong Correlations in La1−xCaxMnO3 at the Magnetocaloric Transition. Physical Review B, 91, Article ID: 134410.
<br>https://doi.org/10.1103/PhysRevB.91.134410Zhao, R., Jin, K., Xu, Z., et al. (2013) The Oxygen Vacancy Effect on the Magnetic Property of the LaMnO3−δ Thin Films. Applied Physics Letters, 102, Article ID: 122402. <br>https://doi.org/10.1063/1.4798550Markovich, V., Rozenberg, E., Gorodetsky, G., et al. (2004) Vacancies at Mn-Sites in LaMn1−xO3 Manganites: Interplay between Ferromagnetic Interactions and Hydrostatic Pressure. Journal of Applied Physics, 95, 7112-7114.
<br>https://doi.org/10.1063/1.1667855Joy, P., Sankar, C.R. and Date, S. (2002) The Limiting Value of x in the Ferromagnetic Compositions La1−xMnO3. Journal of Physics: Condensed Matter, 14, L663. <br>https://doi.org/10.1088/0953-8984/14/39/104Boschker, H., Huijben, M., Vailionis, A., et al. (2011) Optimized Fabrication of High-Quality La0.67Sr0.33MnO3 Thin Films Considering All Essential Characteristics. Journal of Physics D: Applied Physics, 44, Article ID: 205001.
<br>https://doi.org/10.1088/0022-3727/44/20/205001Abdelmoula, N., Guidara, K., Cheikh-Rouhou, A., Dhahri, E. and Joubert, J.C. (2000) Effects of the Oxygen Nonstoichiometry on the Physical Properties of La0.7Sr0.3MnO3−δ□δ manganites (0 ≤ ≤ 0.15). Journal of Solid State Chemistry, 151, 139-144. <br>https://doi.org/10.1006/jssc.2000.8636Ouyang, S., Wang, C., Liu, G., et al. (2008) Oxygen Pressure Dependent Electroresistance in La0.9Sr0.1MnO3 Thin Films Grown by Laser Molecular Beam Epitaxy. Science in China Series G: Physics, Mechanics and Astronomy, 51, 232-236. <br>https://doi.org/10.1007/s11433-008-0035-4Wang, C., Jin, K.-J., Gu, L., et al. (2013) Crucial Role Played by Interface and Oxygen Content in Magnetic Properties of Ultrathin Manganite Films. Applied Physics Letters, 102, Article ID: 252401. <br>https://doi.org/10.1063/1.4812302Ohnishi, T., Shibuya, K., Yamamoto, T., et al. (2008) Defects and Transport in Complex Oxide Thin Films. Journal of Applied Physics, 103, Article ID: 103703. <br>https://doi.org/10.1063/1.2921972Droubay, T.C., Qiao, L., Kaspar, T C., et al. (2010) Nonstoichiometric Material Transfer in the Pulsed Laser Deposition of LaAlO3. Applied Physics Letters, 97, Article ID: 124105. <br>https://doi.org/10.1063/1.3487778Liu, G., Lei, Q. and Xi, X. (2012) Stoichiometry of SrTiO3 Films Grown by Pulsed Laser Deposition. Applied Physics Letters, 100, Article ID: 202902. <br>https://doi.org/10.1063/1.4717984Marozau, I., Das, P.T., Döbeli, M., et al. (2014) Influence of La and Mn Vacancies on the Electronic and Magnetic Properties of LaMnO3 Thin Films Grown by Pulsed Laser Deposition. Physical Review B, 89, Article ID: 174422.
<br>https://doi.org/10.1103/PhysRevB.89.174422Goyal, A., Rajeswari, M., Shreekala, R., et al. (1997) Material Characteristics of Perovskite Manganese Oxide Thin Films for Bolometric Applications. Applied Physics Letters, 71, 2535. <br>https://doi.org/10.1063/1.120427Prellier, W., Rajeswari, M., Venkatesan, T., et al. (1999) Effects of Annealing and Strain on La1−xCaxMnO3 Thin Films: A Phase Diagram in the Ferromagnetic Region. Applied Physics Letters, 75, 1446-1448.
<br>https://doi.org/10.1063/1.124720Ju, H., Nam, Y., Lee, J., et al. (2000) Anomalous Magnetic Properties and Magnetic Phase Diagram of La1−xBaxMnO3. Journal of Magnetism and Magnetic Materials, 219, 1-8. <br>http://doi.org/10.1016/S0304-8853(00)00429-7Chen, X.X., Liu, G.Z., Zhu, X., et al. (2016) Improved Electrical and Magnetic Transport Properties of La0.8Ba0.2MnO3 Thin Films by Oxygen Annealing. Science China Physics, Mechanics & Astronomy, 59, Article ID: 677521.
<br>https://doi.org/10.1007/s11433-016-0020-xZhang, J., Tanaka, H., Kanki, T., et al. (2001) Strain Effect and the Phase Diagram of La1−xBaxMnO3 Thin Films. Physical Review B, 64, Article ID: 184404. <br>https://doi.org/10.1103/PhysRevB.64.184404