Understanding the Anisotropy in the Electrical Conductivity of CuPt-type Ordered GaInP Thin Films by Combining TEM Biasing and First Principles Calculations.

In this work, the effect of CuPt ordering on the optoelectronic properties of GaInP is studied by combining transmission electron microscopy measurements and density functional theory (DFT) calculations. GaInP layers were grown by metal organic vapor phase epitaxy with a CuPt single-variant-induced ordering due to the intentional misorientation of the Ge(001) substrate. Moreover, the degree of order was controlled using Sb as the surfactant without changing other growth parameters.

The effect of Sb-surfactant on GaInP CuPt type ordering: assessment through dark field TEM and aberration corrected HAADF imaging.

We report on the effect of Sb on the microstructure of GaInP layers grown by metal organic vapor phase epitaxy (MOVPE). These layers exhibit a CuPt single variant ordering due to the intentional misorientation of the substrate (Ge(001) substrates with 6° misorientation towards the nearest [111] axis). The use of Sb as a surfactant during the GaInP growth does not modify the type of ordering, but it is found that the order parameter (η) decreases with increasing Sb flux.

Evidence of a minority monoclinic LaNiO phase in lanthanum nickelate thin films.

LaNiO (LNO) thin films of 14 nm and 35 nm thicknesses grown epitaxially on LaAlO (LAO) and (LaAlO)(SrTaAlO) (LSAT) substrates are studied using High Resolution Transmission Electron Microscopy (HRTEM) and High Angle Annular Dark Field (HAADF) imaging. The strain state of the films is studied using Geometric Phase Analysis (GPA). Results show the successful in-plane adaptation of the films to the substrates, both in the compressive (LAO) and tensile (LSAT) cases.

EELS tomography in multiferroic nanocomposites: from spectrum images to the spectrum volume.

Electron Energy Loss Spectroscopy (EELS) in a transmission electron microscope offers the possibility of extracting high accuracy maps of composition and electronic properties through EELS spectrum images (EELS-SI). Acquiring EELS-SI for different tilt angles, a 3D tomographic reconstruction of EELS information can be achieved. In the present work we show that an EELS spectrum volume (EELS-SV), a 4D dataset where every voxel contains a full EELS spectrum, can be reconstructed from the EELS-SI tilt series by the application of multivariate analysis.