Hétérostructures d'oxydes multiferroïques de manganites de terres rares hexagonaux RMnO3 - Elaboration par MOCVD à injection et caractérisations structurales et physiques

Abstract : Bulk hexagonal rare-earth manganites RMnO3 are multiferroic at low temperature: they are simultaneously ferroelectric (TC ~ 900 K) and antiferromagnetic (TN ~ 80 K). We grew RMnO3 and (RMnO3/R'MnO3)n heterostructures, with R = Y, Ho, Er, Dy and Tb, on ZrO2(Y2O3) (111) and Pt (111)/Si substrates, by MOCVD. The films were oriented with the c-axis perpendicular to the substrate plane. DyMnO3 and TbMnO3 hexagonal films were obtained by epitaxial stabilisation. Thickness and composition effects on the structure of the films were studied. The magnetism of the films was explored by neutron diffraction. Antiferromagnetism was evidenced, which order temperature TN decreases with film thickness. The lateral size of the magnetic domains is of the order of 20 - 50 nm. Optical measurements by second harmonic generation showed that the films are ferroelectric at room temperature. A giant magnetocapacitive effect, explained by extrinsic origins, was observed in a (YMnO3/HoMnO3)15 superlattice.
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Contributor : Isabelle Gélard <>
Submitted on : Tuesday, September 7, 2010 - 9:51:40 AM
Last modification on : Tuesday, February 20, 2018 - 1:10:17 AM
Long-term archiving on: Wednesday, December 8, 2010 - 2:36:03 AM

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  • HAL Id : tel-00371409, version 2

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Isabelle Gelard. Hétérostructures d'oxydes multiferroïques de manganites de terres rares hexagonaux RMnO3 - Elaboration par MOCVD à injection et caractérisations structurales et physiques. Matière Condensée [cond-mat]. Institut National Polytechnique de Grenoble - INPG, 2009. Français. ⟨tel-00371409v2⟩

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