Synthesis and characterization of highly textured Pt–Bi thin films

Authors

Xingzhong Li, University of Nebraska - LincolnFollow
Parashu Kharel, University of Nebraska - LincolnFollow
Shah R. Valloppilly, University of Nebraska-LincolnFollow
David J. Sellmyer, University of Nebraska-LincolnFollow

Date of this Version

9-2011

Comments

Published in Philosophical Magazine 91:25 (September 1, 2011), pp. 3406–3415; doi: 10.1080/14786435.2011.580289 Copyright © 2011 Taylor & Francis; http://www.informaworld.com Used by permission.

Abstract

Pt–Bi films were synthesized on glass and thermally oxidized silicon substrates by e-beam evaporation and annealing. The structures were characterized using X-ray diffraction (XRD) and transmission electron microscopy/selected area electron diffraction (TEM/SAED) techniques. Single-phase PtBi was obtained at an annealing temperature of 300°C, whereas a higher annealing temperature of 400°C was required to obtain the highly textured γ-PtBi2 phase. TEM/SAED analysis showed that the films annealed at 400°C contain a dominant γ-PtBi2 phase with a small amount of β-PtBi2 and α-PtBi2 phases. Both the PtBi and γ-PtBi2 phases are highly textured in these two kinds of film: the c-axis of the hexagonal PtBi phase is mostly in the film plane, whereas the c-axis of the trigonal γ-PtBi2 phase is perpendicular to the film plane. The electrical resistivity of the film with the γ-PtBi2 phase was smaller by one order of magnitude than that of the film with the PtBi phase.