The Surface and Interface Microstructure of Epitaxial Pr_0.7Sr_0.3MnO₃/La_0.5Ca_0.5MnO₃ Bilayer Structure

Abstract:

Epitaxial bilayer structure consisting of ferromagnetic (FM) metallic Pr_0.7Sr_0.3MnO₃ (PSMO) and antiferromagnetic (AFM) insulator La_0.5Ca_0.5MnO₃ (LCMO) was fabricated on (001)-oriented single crystal SrTiO₃ (STO) substrate by pulsed laser deposition technique. We studied the surface structure and interdiffusion at interface between PSMO and LCMO by using atomic force microscope and grazing incident x-ray reflectivity (GIXRR). The perfect data fitting result of GIXRR indicated that interdiffusion at the interface of Pr_0.7Sr_0.3MnO₃/La_0.5Ca_0.5MnO₃ (PSMO/LCMO) could not be negligible; there was a large interdiffusion zone at the PSMO/LCMO interfaces with a thickness of about 7 nm. We found that the thickness of the top layer at air/PSMO interface was about 2.5 nm and the mass density of the top layer was about 76.53% of that of PSMO layer. The surface roughness was about 1.6 nm which was consistent with observation by atomic force microscopy. Normal X-ray diffraction (NXRD) was also employed to investigate the average structure. Except from PSMO and LCMO layer diffraction peaks, we observed another additional peak, which was developed from the large disordered layer resulting from interdiffusion at the interface of PSMO/LCMO. This implied that the variation of crystalline structure of PSMO/LCMO film occurred due to interdiffusion. Surface roughness and interdiffusion played an important role in magnetic properties of FM/AFM bilayer.

• Periodical: Applied Mechanics and Materials (Volume 372)
• Pages: 75-79
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.372.75
• Online since: August 2013
• Authors: Haiou Wang, Hao Liu, Meng Xiong Cao, Wei Shi Tan, Ping Dai, Yun Zhang, Qian Gao, Quan Jie Jia, Xiao Shan Wu
• Keywords: Interdiffusion, Interface, Pr_0.7Sr_0.3MnO₃/La_0.5Ca_0.5MnO₃, Surface, X-Ray Reflectivity

References

[1] C. Chappert, A. Fert, F. Nguyen Van Dau, The emergence of spin electronics in data storage, Nature Materials. 6 (2007) 813-823.

DOI: 10.1038/nmat2024

[2] P. Padhan, W. Prellier, Effect of strain on the electrical transport and magnetization of Pr0. 5Ca0. 5MnO3/La0. 5Ca0. 5MnO3/Pr0. 5Ca0. 5MnO3 trilayer structures, Phys. Rev. B. 72 (2005) 094407.

[3] S. Y. Park, Y.H. Hyun, Y. P. Lee, V. L. Svetchnikov, K.W. Kim, V.G. Prokhorov, Evidence for the charge-ordered state and phase separation at room temperature in half-doped La0. 5Ca0. 5MnO3 films, Appl. Phys. Lett. 89 (2006) 052502.

DOI: 10.1063/1.2243340

[4] T. Z. Ward, Z. Gai, X.Y. Xu, H.W. Guo, L.F. Yin, J. Shen , Tuning the metal-insulator transition in manganite films through surface exchange coupling with magnetic nanodots, Phys. Rev. Lett. 106 (2011) 157207.

DOI: 10.1103/physrevlett.106.157207

[5] D. Niebieskikwiat, L. E. Hueso, J. A. Borchers, N. D. Mathur, M. B. Salamon, Nanoscale magnetic structure of ferromagnet/antiferromagnet manganite multilayers, Phys. Rev. Lett. 99 (2007) 247207.

DOI: 10.1103/physrevlett.99.247207

[6] J. Hoppler, J. Stahn, Ch. Niedermayer, V. K. Malik, H. Bouyanfif, A. J. Drew, M. Rössle, A. Buzdin, G. Cristiani, H. -U. Habermeier, B. Keimer, C. Bernhard, Giant superconductivity-induced modulation of the ferromagnetic magnetization in a cuprate-manganite superlattice, Nature Materials. 8 (2009).

DOI: 10.1038/nmat2383

[7] D. K. Satapathy, M. A. Uribe-Laverde, I. Marozau, V. K. Malik, S. Das, Th. Wagner, C. Marcelot, J. Stahn, S. Brück, A. Rühm, S. Macke, T. Tietze, E. Goering, A. Frañó, J. -H. Kim, M. Wu, E. Benckiser, B. Keimer, A. Devishvili, B. P. Toperverg, M. Merz, P. Nagel, S. Schuppler, C. Bernhard, Magnetic proximity effect in YBa2Cu3O7/La2/3Ca1/3MnO3 and YBa2Cu3O7/LaMnO3+δ superlattices, Physical Review Letters. 108 (2012).

DOI: 10.1103/physrevlett.108.197201

[8] H.O. Wang, P. Dai, H. Liu and W. S. Tan, F. Xu, X. S. Wu, Q. J. Jia, G. J. Hu, J. Gao, Magnetic and transport properties of Pr0. 7Sr0. 3MnO3/La0. 5Ca0. 5MnO3/ Pr0. 7Sr0. 3MnO3 trilayers, Int. J. Mod. Phys. B. 26 (2012) 1250132.

DOI: 10.1007/s12034-014-0624-y

[9] REFS Reflectivity Simulation Software (Bede Scientific Instruments, Lindsey Park, Durham, UK, 1996).

[10] W. S. Tan, X.S. Wu,J. Du, J.S. Liu, A. Hu, S.S. Jiang, J. Wang, Z.H. Wu, W. L. Zheng, Q.J. Jia, J. Gao, Microstructures and resistivity of cuprate/manganite bilayer deposited on SrTiO3 substrate, J. Appl. Phys. 93 (2003) 8215.

DOI: 10.1063/1.1541653

[11] S. -W. Han, S. Tripathy, P. F. Miceli, E. Badica, M. covington, L. H. Greene ,M. Aprili, X-ray reflectivity study of interdiffusion at YBa2Cu3O7-x and metal interfaces, Jpn. J. Appl. Phys. 42 (2003) 1395-1399.

DOI: 10.1143/jjap.42.1395

[12] S. -W. Han, J.A. Pitney, P.F. Miceli, M. Covington, L.H. Greene, M.J. Godbole, D.H. Lowndes, X-ray reflectivity study of thin film oxide superconductors, Physica B. 221 (1996) 235-237.

DOI: 10.1016/0921-4526(95)00931-0

[13] G. Palasantzas , Y.P. Zhao, J. Th. M. De Hosson, G. C. Wang, Roughness effects on magnetic properties of thin films, Physica B. 283 (2000) 199-202.

DOI: 10.1016/s0921-4526(99)01939-0

[14] J. Swerts, K. Temst, N. Vandamme, C. Van Haesendonck, Y. Bruynseraede, Interplay between surface roughness and magnetic properties in Ag/Fe bilayers, Journal of Magnetism and Magnetic Materials. 240 (2002) 380-382.

DOI: 10.1016/s0304-8853(01)00832-0

[15] A. Maitre, D. Ledue, R. Patte, Interfacial roughness and temperature effects on exchange bias properties in coupled ferromagnetic/antiferromagnetic bilayers, Journal of Magnetism and Magnetic Materials. 324 (2012) 403-409.

DOI: 10.1016/j.jmmm.2011.07.049

[16] S. Colis, G. Schmerber, A. Dinia, Correlation between magnetic and transport properties of Co/Ir/Co sandwiches and surface roughness, Thin Solid Films. 380 (2000) 137-141.

DOI: 10.1016/s0040-6090(00)01488-7