TiOx thin films grown on Pd(100) and Pd(111) by chemical vapor deposition
Artikel i vetenskaplig tidskrift, 2016

The growth of ultrathin TiOx (0 <= x <= 2) films on Pd(100) and Pd(111) surfaces by chemical vapor deposition (CVD), using Titanium(IV)isopropoxide (TTIP) as precursor, has been investigated by high resolution photoelectron spectroscopy, low energy electron diffraction and scanning tunneling microscopy. Three different TiOx phases and one Pd-Ti alloy phase have been identified for both surfaces. The Pd-Ti alloy phase is observed at the initial stages of film growth. Density functional theory (DFT) calculations for Pd(100) and Pd(111) suggest that Ti is alloyed into the second layer of the substrate. Increasing the TTIP dose yields a wetting layer comprising Ti2+ species (TiOx, x similar to 0.75). On Pd(100), this phase exhibits a mixture of structures with (3 x 5) and (4 x 5) periodicity with respect to the Pd(100) substrate, while an incommensurate structure is formed on Pd(111). Most importantly, on both surfaces this phase consists of a zigzag pattern similar to observations on other reactive metal surfaces. Further increase in coverage results in growth of a fully oxidized (TiO2) phase on top of the partially oxidized layer. Preliminary investigations indicate that the fully oxidized phase on both Pd(100) and Pd(111) may be the TiO2(B) phase. (C) 2016 Elsevier B.V. All rights reserved.

Low energy electron diffraction

TiOx thin films

Density functional calculations

Scanning tunneling microscopy

Pd

Photoemission spectroscopy

Författare

M. H. Farstad

Norges teknisk-naturvitenskapelige universitet

D. Raggazzon

Uppsala universitet

Henrik Grönbeck

Chalmers, Fysik, Kemisk fysik

Kompetenscentrum katalys (KCK)

M.D. Strömsheim

Norges teknisk-naturvitenskapelige universitet

C. Stavrakas

Uppsala universitet

J. Gustafson

Lunds universitet

A. Sandell

Uppsala universitet

A. Borg

Norges teknisk-naturvitenskapelige universitet

Surface Science

0039-6028 (ISSN)

Vol. 649 80-

Drivkrafter

Hållbar utveckling

Styrkeområden

Nanovetenskap och nanoteknik

Materialvetenskap

Fundament

Grundläggande vetenskaper

Infrastruktur

C3SE (Chalmers Centre for Computational Science and Engineering)

Ämneskategorier

Materialkemi

Teoretisk kemi

Den kondenserade materiens fysik

DOI

10.1016/j.susc.2016.02.002

Mer information

Senast uppdaterat

2018-04-20