Characterization of epitaxial LSMO thin films with high Curie temperature prepared on different substrates. (April 2016)

• Record Type: Journal Article
• Authors: Španková, M.; Štrbík, V.; Dobročka, E.; Chromik, Š.; Sojková, M.; Zheng, D.N.; Li, J.
• Is Part Of: Vacuum. Volume 126(2016)
• Page Start: 24
• Page End: 28
• Publication Date: 2016-04
• Subjects: Epitaxial LSMO film -- Substrate-induced strain -- Curie temperature -- Metal-insulator transition temperature; Vacuum -- Periodicals; 621.55
• DOI: 10.1016/j.vacuum.2016.01.009
• Languages: English
• ISSNs: 0042-207X

Abstract

Abstract: We investigated structural, electrical and magnetic properties of epitaxial La0.67 Sr0.33 MnO3 (LSMO) thin films (20–100 nm thick) deposited by pulsed laser ablation on different substrates. Single crystalline substrates: (001) SrTiO3, (001) LaAlO3, (001) La0.26 Sr0.76 Al0.61 Ta0.37 O3 and (001) MgO were used to vary the substrate-induced epitaxial strain. The LSMO films exhibit very good crystal quality and enhanced temperatures of metal-insulator transition (TMI ) as well as temperature of ferromagnetic ordering (Curie temperature, TC ) up to 451 K with TMI = TC coincidence of both temperatures. The enhanced TC (TMI ) values were analyzed with respect to substrate-induced strain and LSMO film thickness. We ascribe the increased TC (TMI ) values to decreasing strength of electron-phonon coupling coming from Jahn-Teller splitting. The substrate-induced strain in the LSMO films only decreased the TC (TMI ) values depending on magnitude of biaxial strain. Highlights: Epitaxial La0.67 Sr0.33 MnO3 (LSMO) films are grown on SrTiO3, LaAlO3, La0.26 Sr0.76 Al0.61 Ta0.37 O3 and MgO substrates. LSMO films exhibit high Curie temperature TC and metal-insulator transition temperature TMI in temperature range 405–450 K. TC (TMI ) is analyzed with respect to substrate-induced strain. Increased TC (TMI ) values are ascribed to decreasing strength of electron-phonon coupling. Substrate-induced strain slightly reduces TC (TMI ) values.