Presentation is loading. Please wait.

Presentation is loading. Please wait.

Applications of MeV Ion Channeling and Backscattering to the Study of Metal/Metal Epitaxial Growth Richard J. Smith Physics Department Montana State University.

Published by Modified over 9 years ago

Similar presentations

Presentation on theme: "Applications of MeV Ion Channeling and Backscattering to the Study of Metal/Metal Epitaxial Growth Richard J. Smith Physics Department Montana State University."— Presentation transcript:

1 Applications of MeV Ion Channeling and Backscattering to the Study of Metal/Metal Epitaxial Growth Richard J. Smith Physics Department Montana State University Bozeman MT 59715

2 MSU Colloquium 10/5/012 Outline: ä Overview of program and techniques ä Ti/Al(100) epitaxial fcc overlayer ä Ag/Al(100) epitaxial alloyed overlayer ä Ni/Al(110) disordered alloy formation

3 MSU Colloquium 10/5/013 Acknowledgements ä Ph.D students: Adli Saleh,V. Shuthanandan, N. Shivaparan N. Shivaparan ä Dr. Yong-wook Kim (from ASSRC) ä National Science Foundation ä http://www.physics.montana.edu/Ionbeams/ionbeams.html

4 MSU Colloquium 10/5/014 Metal-metal Interface Structure ä Understand overlayer growth and alloy formation ä Chemical composition and structure of the interface ä Applications: magnetoresistive devices, spin electronics ä Surface energy (broken bonds) ä Chemical formation energy ä Strain energy A B interface

5 MSU Colloquium 10/5/015 Metal-metal systems studied... ä Substrates: Al(111), Al(100), Al(110) ä Metal overlayers studied so far: ä Fe, Ni, Co, Pd ä Ti, Ag, Zr ä All have surface energy > Al surface energy ä All form Al compounds with  H form < 0 ä Use resistively heated wires ( ~ML/min) ä Deposit on substrate at room temperature (atomic size smaller than Al) (atomic size smaller than Al) (atomic size larger than Al)

6 MSU Colloquium 10/5/016 MSU Ion Beam Laboratory

7 MSU Colloquium 10/5/017 2 MV van de Graaff Accelerator

8

9 MSU Colloquium 10/5/019 Scattering chamber ä High precision sample goniometer ä Hemispherical VSW analyzer (XPS, ISS) ä Ion and x-ray sources ä LEED ä Metal wires for film deposition

10 MSU Colloquium 10/5/0110 Overview of High Energy Ion Scattering (HEIS) ä MeV He + ions ä Yield = Q   (Nt) ä Ni peak for coverage ä Al peak for structure

11 MSU Colloquium 10/5/0111 Angular Yield (Channeling dip) ä 1 MeV He + ä Al bulk yield ä Ag surface peak ä  inc = 0 o ä  det = 105 o ä ~10 15 ions/cm 2 ä  min = 3.6%

12 MSU Colloquium 10/5/0112 1. Ti on Al(100) surface peaks ä Surface peaks (SP) ä Decrease in Al SP area ä Ti shadows Al atoms ä FCC

13 MSU Colloquium 10/5/0113 HEIS: Al surface peak area vs. Ti coverage ä Decrease in Al SP (o) to 5.5 ML ä Simulation () for flat Ti layer in FCC Al sites ä Critical thickness of 5 ML ~ 4.4% lattice mismatch ä Increase > 5 ML Ti layer relaxation

14 MSU Colloquium 10/5/0114 Ti on Al(100): XPD angular scans ä Enhanced Al 2p emission at 0 o, 45 o ä Forward scattering for FCC lattice ä Ti 2p photopeaks show enhanced emission along same directions ä FCC Ti film !

15 MSU Colloquium 10/5/0115 Ti on Al(001): HEIS Channeling ä Channeling along (101) shows outward relaxation for Ti layer ä a  = 2.07 Å HEIS ä a  = 2.12Å XPD ä FCC Ti was also confirmed by LEED IV analysis

16 MSU Colloquium 10/5/0116 Interstitial substitution T > 300 o C ä Fcc Ti is stable for T  300 o C ä At 400 o C Ti diffuses to depth ~ 300Å ä In channeling direction see Ti shadowing 300 o C 400 o C

17 MSU Colloquium 10/5/0117 Interstitial substitution T = 400 o C ä Channeling normal to (110) surface ä Plot Ti SP area and bulk Al yield ä Fractional Ti occupation is ~ 93%

18 MSU Colloquium 10/5/0118 Ti on Al(111): XPD Ti and Al ä Ti and Al emission are clearly different and consistent with the hcp and fcc structures ä Ti grows on Al(111) with hcp structure ä Fcc stacking in Al does not prevent hcp stacking in Ti ä Recent XRD studies on Ti stacking in Ti-Al multilayers still under discussion

19 MSU Colloquium 10/5/0119 2: Ag on Al(100):Al surface peak ä Ag shadows Al surface atoms ä Shadowing not like that for flat Ag overlayer ä Not Ag islands on FCC lattice ä Small strain at interface(0.9%)

20 MSU Colloquium 10/5/0120 Ag on Al(100): Ag surface peak ä Ag atoms are shadowed at high coverage ä Well-ordered Ag film ä Confirmed by LEED

21 MSU Colloquium 10/5/0121 Ag on Al(100) LEED patterns A. Clean B. 0.5 ML C. 2.5 ML D. 3.6 ML E. 30 ML F. 30 ML heated to 250 o C

22 MSU Colloquium 10/5/0122 Ag on Al(100): Ag binding energy (BE) ä Ag 3d energy decreases gradually ä Ag 4d (VB) also changes ä BE shift is similar to bulk Al-Ag alloys ä Ag moves into Al surface AlAg 2 Al+dilute Ag

23 MSU Colloquium 10/5/0123 3: Ni on Al(110) Al surface peaks ä Al SP area increases with Ni coverage ä 3 regions with different slopes (2) (0.35) (~0) ä No LEED spots ä Interface alloy forms at room temperature

24 MSU Colloquium 10/5/0124 Ni on Al(110):XPS chemical shifts ä Shifts in BE ä Shifts in satellite ä Compare with XPS for bulk alloys to identify surface composition NiAl 3 1.05eV Ni 2 Al 0.75eV (8.0 eV) NiAl 0.2 eV (7.2 eV) Ni 3 Al 0.0 eV (6.5 eV) Ni 0.0 eV (5.8 eV)

25 MSU Colloquium 10/5/0125 Snapshots from MC simulations Al(110)+0.5 ML Ni Clean Al(110) Al(110)+2.0 ML Ni ä MC (total energy) using EAM potentials for Ni, Al (Voter) ä Equilibrate then add Ni in 0.5 ML increments (solid circles) ä Ion scattering simulations (VEGAS)

26 MSU Colloquium 10/5/0126 Ni on Al(110):HEIS simulations using the snapshots ä Measured (o) Simulation (  ) ä Slopes agree ä Change at 2 ML correct ä Use snapshots for insight ä Ni atoms move below the surface

27 MSU Colloquium 10/5/0127 Conclusions: ä Combined HEIS, XPS, LEED to study film structures on solid-solid interfaces ä Ti/Al(100) epitaxial fcc overlayer up to 5 ML ä Ag/Al(100) epitaxial overlayer with some alloying of Al into the Ag overlayer ä Ni/Al(110) disordered alloy formation for deposition at room temperature

28 MSU Colloquium 10/5/0128 Techniques used... ä High-energy ion scattering and channeling (HEIS) ä X-ray photoemission - intensities and chemical shifts in binding energy (XPS) shifts in binding energy (XPS) ä X-ray photoelectron diffraction (XPD) ä Low-energy electron diffraction (LEED) ä Low-energy ion scattering (LEIS)

29 MSU Colloquium 10/5/0129 Ti on Al(100): XPS intensity vs Ti coverage ä Attenuation follows flat film model (solid line) after 2 ML ä No decrease of intensity for first monolayer ä Possible Ti-Al interchange at top layer

30 MSU Colloquium 10/5/0130 Ti on Al(110): HEIS Al surface peak vs Ti coverage ä Shadowing of Al atoms by Ti same as for Al(001) ä Critical thickness at ~5 ML ä Simulation (  ) for flat Ti layer in FCC Al sites ä Film relaxes for coverage > 5 ML

31 MSU Colloquium 10/5/0131 Ti on Al(111): HEIS/Channeling ä Channeling dips at normal incidence ä Ti is shadowed so have ordered film on Al surface ä Ti and Al axes are aligned normal to surface

32 MSU Colloquium 10/5/0132 Ti on Al(111): HEIS Al SP vs Ti coverage ä Al SP area initially decreases ä Ti shadows Al atoms ä After 2 ML the Al SP increases as if Al is disordered or alloyed ä XPD, LEED, ISS, XPS indicate ordered Ti film on ordered Al ä Dechanneling ?

33 MSU Colloquium 10/5/0133 Angular Yield (Channeling dip) ä 1 MeV He + ä Al bulk yield ä Ag surface peak ä  inc = 0 o ä  det = 105 o ä ~10 15 ions/cm 2 ä  min = 3.6%

34 MSU Colloquium 10/5/0134 Ag on Al(100): XPS intensities ä Rapid decrease of Al peak ä Rapid growth of Ag peak ä Growth of Ag islands for high coverage ä Flat film grows at first but not pure Ag

Download ppt "Applications of MeV Ion Channeling and Backscattering to the Study of Metal/Metal Epitaxial Growth Richard J. Smith Physics Department Montana State University."

Similar presentations

Speaker: Xiangshi Yin Instructor: Elbio Dagotto Time: April 15, 2010 (Solid State II project) Quantum Size Effect in the Stability and Properties of Thin.

Speaker: Xiangshi Yin Instructor: Elbio Dagotto Time: April 15, 2010 (Solid State II project) Quantum Size Effect in the Stability and Properties of Thin.
2 nd FEZA School On Zeolites 1-2 September 2008, Paris X-ray photoelectron spectroscopy and its use for solid materials Jacques C. Védrine.

2 nd FEZA School On Zeolites 1-2 September 2008, Paris X-ray photoelectron spectroscopy and its use for solid materials Jacques C. Védrine.
International Workshop on High-Volume Experimental Data, Computational Modeling and Visualization Xiangshan, 17-19 October 2011 Determining the composition.

International Workshop on High-Volume Experimental Data, Computational Modeling and Visualization Xiangshan, October 2011 Determining the composition.
Plan : lattices Characterization of thin films and bulk materials using x-ray and electron scattering V. Pierron-Bohnes IPCMS-GEMME, BP 43, 23 rue du Loess,

Plan : lattices Characterization of thin films and bulk materials using x-ray and electron scattering V. Pierron-Bohnes IPCMS-GEMME, BP 43, 23 rue du Loess,
Electron Spectroscopies of InN grown by HPCVD Department of Physics and Astronomy Georgia State University Atlanta, Georgia Rudra P. Bhatta Solid State.

Electron Spectroscopies of InN grown by HPCVD Department of Physics and Astronomy Georgia State University Atlanta, Georgia Rudra P. Bhatta Solid State.
Influence of Substrate Surface Orientation on the Structure of Ti Thin Films Grown on Al Single- Crystal Surfaces at Room Temperature Richard J. Smith.

Influence of Substrate Surface Orientation on the Structure of Ti Thin Films Grown on Al Single- Crystal Surfaces at Room Temperature Richard J. Smith.
1 EFFECTS OF CARBON REDEPOSITION ON TUNGSTEN UNDER HIGH-FLUX, LOW ENERGY Ar ION IRRADITAION AT ELEVATED TEMPERATURE Lithuanian Energy Institute, Lithuania.

1 EFFECTS OF CARBON REDEPOSITION ON TUNGSTEN UNDER HIGH-FLUX, LOW ENERGY Ar ION IRRADITAION AT ELEVATED TEMPERATURE Lithuanian Energy Institute, Lithuania.
CMSELCMSEL Hanyang Univ. Differences in Thin Film Growth Morphologies of Co-Al Binary Systems using Molecular Dynamics Simulation : In cases of Co on Co(001),

CMSELCMSEL Hanyang Univ. Differences in Thin Film Growth Morphologies of Co-Al Binary Systems using Molecular Dynamics Simulation : In cases of Co on Co(001),
Grazing incident X-ray Diffraction (XRD) X-rays are electromagnetic radiation with very short wavelength (  10 -8 - 10 -12 m), very suitable to do diffraction.

Grazing incident X-ray Diffraction (XRD) X-rays are electromagnetic radiation with very short wavelength (  m), very suitable to do diffraction.
Catalysis and Catalysts - XPS X-Ray Electron Spectroscopy (XPS)  Applications: –catalyst composition –chemical nature of active phase –dispersion of active.

Catalysis and Catalysts - XPS X-Ray Electron Spectroscopy (XPS)  Applications: –catalyst composition –chemical nature of active phase –dispersion of active.
Alternative representation of QW Phase accumulation model.

Alternative representation of QW Phase accumulation model.
IPCMS-GEMME, BP 43, 23 rue du Loess, Strasbourg Cedex 2

IPCMS-GEMME, BP 43, 23 rue du Loess, Strasbourg Cedex 2
MORPHOLOGY AND STRAIN-INDUCED DEFECT STRUCTURE OF FE/MO(110) ULTRATHIN FILMS: IMPLICATIONS OF STRAIN FOR MAGNETIC NANOSTRUCTURES I. V. Shvets Physics Department.

MORPHOLOGY AND STRAIN-INDUCED DEFECT STRUCTURE OF FE/MO(110) ULTRATHIN FILMS: IMPLICATIONS OF STRAIN FOR MAGNETIC NANOSTRUCTURES I. V. Shvets Physics Department.
Alloy Formation at the Co-Al Interface for Thin Co Films Deposited on Al(001) and Al(110) Surfaces at Room Temperature* N.R. Shivaparan, M.A. Teter, and.

Alloy Formation at the Co-Al Interface for Thin Co Films Deposited on Al(001) and Al(110) Surfaces at Room Temperature* N.R. Shivaparan, M.A. Teter, and.
Epitaxial Overlayers vs Alloy Formation at Aluminum- Transition Metal Interfaces Richard J. Smith Physics Department Montana State University Bozeman MT.

Epitaxial Overlayers vs Alloy Formation at Aluminum- Transition Metal Interfaces Richard J. Smith Physics Department Montana State University Bozeman MT.
Alloy Formation at the Epitaxial Interface for Ag Films Deposited on Al(001) and Al(110) Surfaces at Room Temperature* N.R. Shivaparan, M.A. Teter, and.

Alloy Formation at the Epitaxial Interface for Ag Films Deposited on Al(001) and Al(110) Surfaces at Room Temperature* N.R. Shivaparan, M.A. Teter, and.
One-dimensional Ostwald Ripening on Island Growth An-Li Chin ( 秦安立 ) Department of Physics National Chung Cheng University Chia-Yi 621 Taiwan, ROC Prof.

One-dimensional Ostwald Ripening on Island Growth An-Li Chin ( 秦安立 ) Department of Physics National Chung Cheng University Chia-Yi 621 Taiwan, ROC Prof.
NWAPS-May 2000 1 Evolution of Ni-Al interface alloy for Ni deposited on Al surfaces at room temperature R. J. Smith and V. Shutthanandan* Physics Department,

NWAPS-May Evolution of Ni-Al interface alloy for Ni deposited on Al surfaces at room temperature R. J. Smith and V. Shutthanandan* Physics Department,
CMP Seminar MSU 10/18/ 2000 1 What makes Surface Science “surface” science ? R. J. Smith Physics Department, Montana State Univ. Work supported by NSF.

CMP Seminar MSU 10/18/ What makes Surface Science “surface” science ? R. J. Smith Physics Department, Montana State Univ. Work supported by NSF.
X-ray Photoelectron Spectroscopy —— Application in Phase-switching Device Study Xinyuan Wang A53073806.

X-ray Photoelectron Spectroscopy —— Application in Phase-switching Device Study Xinyuan Wang A

Similar presentations

Ads by Google