Mark Kimbell Prof. Takoudis Manish Singh Yi Yang.

of 28 /28
Chemical Vapor Deposition of NiFe 2 O 4 using Nickelocene and N-butylferrocene Mark Kimbell Prof. Takoudis Manish Singh Yi Yang

Embed Size (px)

Transcript of Mark Kimbell Prof. Takoudis Manish Singh Yi Yang.

Page 1: Mark Kimbell Prof. Takoudis Manish Singh Yi Yang.

Chemical Vapor Deposition of NiFe2O4 using Nickelocene and N-butylferroceneMark KimbellProf. TakoudisManish Singh

Yi Yang

Page 2: Mark Kimbell Prof. Takoudis Manish Singh Yi Yang.

Project

Chemical Vapor Deposition Nickel Oxide (NiO) using Ni(C5H5)2

Iron Oxide (Fe2O3) using FeC14H18

Nickel Ferrite (NiFe2O4)▪ Choose appropriate conditions based on NiO

and Fe2O3 growth rates

▪ XPS to analyze chemical composition▪ XRD to analyze crystalline structure

Page 3: Mark Kimbell Prof. Takoudis Manish Singh Yi Yang.

Background

The magnetoelectric (ME) effect Ferroelectric and ferromagnetic coupling▪ Magnetic switching by an applied electric

field▪ Electric polarity switching by an applied

magnetic field

Page 4: Mark Kimbell Prof. Takoudis Manish Singh Yi Yang.

Magnetoelectric Materials

Uses Memory storage devices Tunable microwave devices Sensors Transducers

C Israel, ND Mathur & JF Scott, Nature Materials 7 (2008) 93

Page 5: Mark Kimbell Prof. Takoudis Manish Singh Yi Yang.

Magnetoelectric Composites

Magnetoelectric composites Made up of a piezoelectric

layer and a magnetostrictive layer

NiFe2O4

Page 6: Mark Kimbell Prof. Takoudis Manish Singh Yi Yang.

Chemical Vapor Deposition (CVD)

Argon gas

Oxygen gas

Quartz tube

Heater

Vacuum pump

Substrate

Page 7: Mark Kimbell Prof. Takoudis Manish Singh Yi Yang.

Precursors

Source of the vapor which is fed into the reaction chamber

NICKELOCENE

Ni(C5H5)

2

N-BUTYLFERROCENE

C14H18Fe

Page 8: Mark Kimbell Prof. Takoudis Manish Singh Yi Yang.

8

Nickel Oxide Data

Nickel Oxide Growth Rate(Reactor = 400 oC)

Temperature of Nickelocene (oC)

Page 9: Mark Kimbell Prof. Takoudis Manish Singh Yi Yang.

9

Iron Oxide Data

Temperature of N-Butylferrocene (oC)

Gro

wth

Rate

(nm

/min

)

Iron Oxide Growth Rate(Reactor = 500 oC)

Page 10: Mark Kimbell Prof. Takoudis Manish Singh Yi Yang.

Important Results

Treactor = 400oC Tnickelocene = 60oC

Treactor = 400oC Tn-butylferrocene =

65oC

NiO growth rate = 4.6 nm/min

Fe2O3 growth rate = 8.5 – 9 nm/min

Page 11: Mark Kimbell Prof. Takoudis Manish Singh Yi Yang.

The Plan

CyclesTnickelocene Tn-butylferrocene Treactor NiO deposition time (s) Fe2O3 deposition time (s) Cycles60 65 400 60 30 560 65 400 12 6 20

Co-depositionTnickelocene Tn-butylferrocene Treactor Deposition time (min)60 65 400 1060 60 400 10

Page 12: Mark Kimbell Prof. Takoudis Manish Singh Yi Yang.

X-Ray Photoelectron Spectroscopy (XPS)

Uses x-rays to knock electrons free from surface

Measures kinetic energy of electrons to determine chemical composition

http://www.sckcen.be/microstructure/Infrastructure/XPS/Infrastructure_XPS.htm

Page 13: Mark Kimbell Prof. Takoudis Manish Singh Yi Yang.

XPS Results

Longer cycles (5 cycles, 90 seconds each)

Element

Atomic Conc. (%)

Ni 23.13

Fe 27.30

O 37.31

C 12.27

Ni 2p

Fe 2pO 1s

C 1s

Page 14: Mark Kimbell Prof. Takoudis Manish Singh Yi Yang.

XPS Results

Shorter cycles (20 cycles, 18 seconds each)

Element

Atomic Conc. (%)

Ni 24.82

Fe 28.81

O 39.40

C 6.97

Ni 2p

Fe 2pO 1s

C 1s

Page 15: Mark Kimbell Prof. Takoudis Manish Singh Yi Yang.

XPS Results

Co-Deposition

Element

Atomic Conc. (%)

Ni 26.50

Fe 22.69

O 30.29

C 20.52

Ni 2p

Fe 2p

O 1s

C 1s

Tnickelocene Tn-butylferrocene Treactor

60oC 65oC 400oC

Page 16: Mark Kimbell Prof. Takoudis Manish Singh Yi Yang.

XPS Results

Co-Deposition

Element

Atomic Conc. (%)

Ni 29.17

Fe 22.11

O 31.07

C 17.65

Ni 2p

Fe 2p

O 1s

C 1s

Tnickelocene Tn-butylferrocene Treactor

60oC 60oC 400oC

Page 17: Mark Kimbell Prof. Takoudis Manish Singh Yi Yang.

XPS Results – Iron

700705710715720725730735740745750

Binding Energy (eV)

Inte

nsi

ty (

a. u

.)

Peaks correspond to Fe(III) oxidation state

* S. A. Chambers, Y. J. Kim, and Y. Gao Surf. Sci. Spectra 5 219 (1998)

*

Page 18: Mark Kimbell Prof. Takoudis Manish Singh Yi Yang.

XPS Results – Nickel

840850860870880890900

Binding Energy (eV)

Inte

nsi

ty (

a. u

.)

* A. N. Mansour, Surf. Sci. Spectra 3 231 (1994)

Peaks correspond to Ni(II) oxidation state

*

Page 19: Mark Kimbell Prof. Takoudis Manish Singh Yi Yang.

XPS Results

Do not indicate the presence of NiFe2O4

Probably due to interactions between the two gases

Presence of carbon From atmosphere▪ Argon sputtering

From unreacted precursor▪ Due to relatively low deposition temperature

Page 20: Mark Kimbell Prof. Takoudis Manish Singh Yi Yang.

Summary

XPS revealed the presence of both Ni(II) and Fe(III)

The ratio of Ni to Fe did not indicate NiFe2O4

Different deposition conditions must be used in order to achieve the correct ratios Higher reactor temperature Higher iron precursor temperature Lower nickel precursor temperature

Page 21: Mark Kimbell Prof. Takoudis Manish Singh Yi Yang.

Future Work

Try different deposition conditions to deposit NiFe2O4 thin films

X-ray diffraction (XRD) on NiFe2O4 thin films to determine crystalline structure

Anneal to reduce carbon contamination, correct defects / change crystal structure

Page 22: Mark Kimbell Prof. Takoudis Manish Singh Yi Yang.

References

E. Ascher, H. Rieder, H. Schmid, and H. Stössel, J. Appl. Phys. 37 (1966) 1404

W. Eerenstein, N. D. Mathur and J. F. Scott, Nature 442, (2006) 759-765

A.M.J.G. Van Run, D.R. Terrell, and J.H. Scholing, Journal of Materials Science 9 (1974) 1710-1714

W. Yeh and M. Matsumura, Jpn. J. Appl. Phys. Vol. 36 (1997) Pt. 1, No. 11

M. Singh, Y. Yang, and C.G. Takoudis, Journal of The Electrochemical Society, 155 (9) (2008) D618-D623

S.A. Chambers, Y.J. Kim, and Y. Gao, Surf. Sci. Spectra 5 (1998) 219

S. Oswald and W. Bruckner, Surf. Interface Anal. 36 (2004) 17–22

http://www.sckcen.be/microstructure/Infrastructure/XPS/Infrastructure_XPS.htm

Page 23: Mark Kimbell Prof. Takoudis Manish Singh Yi Yang.

Acknowledgements

EEC-NSF Grant # 0755115 Dr. Christos Takoudis Graduate students: Yi Yang, Manish

Singh, Qian Tao

Page 24: Mark Kimbell Prof. Takoudis Manish Singh Yi Yang.

Questions?

Page 25: Mark Kimbell Prof. Takoudis Manish Singh Yi Yang.

Cycling

Argon gas

Oxygen gas

Quartz tube

Heater

Vacuum pump

Substrate

Cycling

Page 26: Mark Kimbell Prof. Takoudis Manish Singh Yi Yang.

Co-Deposition

Argon gas

Oxygen gas

Quartz tube

Heater

Vacuum pump

Substrate

Co-Deposition

Page 27: Mark Kimbell Prof. Takoudis Manish Singh Yi Yang.

Experiment – Setup

Temperaturecontrollers

Precursorcontainers

Reaction chamber

Cold trap

Vacuum pump

• nickelocene• n-butylferrocene

Page 28: Mark Kimbell Prof. Takoudis Manish Singh Yi Yang.

Ellipsometer

Used to measure film thickness

Light source

Polarizer SampleAnalyzer

Θ