Poisson ratio and bulk lattice constant of (Sr 0.25 La 0.75 )CrO 3 from strained epitaxial thin films

International audienceAbout 30 nm thick (001)-oriented (Sr0.25La0.75)CrO3 (SLCO) epitaxial thin films were grown by solid-source oxide molecular beam epitaxy on four different single-crystalline cubic or pseudo-cubic (001)-oriented oxide substrates: LaAlO3, (LaAlO3)0.3(Sr2AlTaO6)0.7, SrTiO3 and DyScO3, which result in lattice mismatch ranging from-2% to +1.7%. All the films are of high-quality, flat and strained by the substrates. By assessing the evolution of the out-of-plane lattice parameter as a function of the in-plane lattice parameter of the samples, we determine both the Poisson ratio (ν = 0.32) and the bulk lattice constant (ab = 3.876 Å) of SLCO. The Poisson ratio significantly differs from LaCrO3 (ν = 0.23) and the (SrxLa1-x)CrO3 solid solution appears to obey structural Vegard's law. Since SLCO is the only one p-type transparent conductive oxide of perovskite structure and has promising thermoelectric properties, integrating SLCO in heterostructures and devices is therefore of paramount importance, which confers on our results their strong interest. Besides, the method used here can be straightforwardly applied to other complex oxides

Low-Density InAs Quantum Dots Grown on InP(001) Using Solid-Source Molecular Beam Epitaxy with a Post-Growth Annealing Process

International audienc

Structure and morphology of Ge nanowires on Si(001): Importance of the Ge islands on the growth direction and twin formation

International audienceUnderstanding and controlling the structural properties of Ge nanowires are important for their current and future use in technological applications. In this study, the initial stages of the heteroepitaxial growth of Ge nanowires on Si(001) via the Au catalyzed vapor-liquid-solid (VLS) method are investigated. We observe a Ge island located at the base of each nanowire. We propose that these islands are formed by the VLS mechanism and initiate the nanowire growth. Analysis of the islands morphology helps to explain the 〈011〉 growth direction commonly observed for Ge nanowires. Moreover, our observations provide an insight into the formation of twins that propagate along the growth direction

P-type thermoelectric LaCrO3-based epitaxial thin films grown by MBE

International audienc

Structural properties of strained epitaxial La 1+δ CrO 3 thin films

International audienc

Optical properties of hybrid structures based on ferroelectric polymers and III-V nanowires grown on silicon substrate

International audienc

Oxidized Titanium Tungsten Surface Functionalization by Silane-, Phosphonic Acid-, or Ortho-dihydroxyaryl-Based Organolayers

International audienc