Resolving mass spectral overlaps in atom probe tomography by isotopic substitutions - case of TiSiN.

Mass spectral overlaps in atom probe tomography (APT) analyses of complex compounds typically limit the identification of elements and microstructural analysis of a material. This study concerns the TiSiN system, chosen because of severe mass-to-charge-state ratio overlaps of the N and Si peaks as well as the N and Si peaks. By substituting N with N, mass spectrum peaks generated by ions composed of one or more N atoms will be shifted toward higher mass-to-charge-state ratios, thereby enabling the separation of N from the predominant Si isotope.

Current-voltage characterization of individual as-grown nanowires using a scanning tunneling microscope.

Utilizing semiconductor nanowires for (opto)electronics requires exact knowledge of their current-voltage properties. We report accurate on-top imaging and I-V characterization of individual as-grown nanowires, using a subnanometer resolution scanning tunneling microscope with no need for additional microscopy tools, thus allowing versatile application. We form Ohmic contacts to InP and InAs nanowires without any sample processing, followed by quantitative measurements of diameter dependent I-V properties with a very small spread in measured values compared to standard techniques.