Coupled magnetic and structural transitions in La0.7Sr0.3MnO3 films on SrTiO3

M Ziese,A Lotnyk,D Hesse,I Vrejoiu,A Setzer

doi:10.1088/1367-2630/10/6/063024

M Ziese, A Lotnyk + Show 3 more

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https://doi.org/10.1088/1367-2630/10/6/063024

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Abstract

The magnetic properties of three epitaxial La0.7Sr0.3MnO3 films of thickness 5, 15 and 40 nm grown on SrTiO3 (001) substrates were investigated. The structural transition of the SrTiO3 substrate induces a magnetic transition in the manganite films due to magnetoelastic coupling. Below the temperature of the structural transition additional steps in the magnetization reversal characteristics appear characterized by clearly defined coercive fields. These additional coercive fields depend on the cooling history of the sample and are related to the formation of structural domains in the La0.7Sr0.3MnO3 films induced by the substrate.

Highlights

Manganite films of the type La0.7Sr0.3MnO3 (LSMO) continue to attract considerable research interest due to the strong spin–charge–phonon coupling [1]
It is well established that both the resistivity and magnetization of LSMO films grown on BaTiO3 substrates undergo large changes at the firstorder structural phase transitions of BaTiO3 at 278 and 183 K [2, 4]
The influence of the structural phase transition at 105 K in SrTiO3 (STO) is less well studied, SrTiO3 is a standard substrate for manganite film growth

Summary

Introduction

Manganite films of the type La0.7Sr0.3MnO3 (LSMO) continue to attract considerable research interest due to the strong spin–charge–phonon coupling [1]. The twinning in the LCMO film was interpreted as arising from a structural transition from a tetragonal high temperature to a low temperature orthorhombic, bulk-like phase induced by the effective stress exerted by the substrate [7]. The evolution of this phase on cooling through the structural transition was not studied. In another study the influence of the cubic to rhombohedral phase transition in LaAlO3 on the structural and magnetic properties of La0.7Sr0.3MnO3 films was investigated [8]. This study differs from the one in [7] in two ways: firstly, by the use of LSMO films instead of LCMO with LSMO being rhombohedral in the bulk and secondly, by the choice of thin films that were fully strained

Experimental details

Results and discussion

Conclusions