Basic Overview Kinetically Controlled Vapor Diffusion Synthesis Of Chromium Doped Indium Hydroxide T

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Basic Overview Kinetically Controlled Vapor
Diffusion Synthesis Of Chromium Doped Indium
Hydroxide Thin Films

• Faculty Advisor Dr. Dan Morse
• Research Mentors Dr. Birgit Schwenzer, James
  Neilson
• RET Advisor Dr. Martina Michenfelder
• RET Participant Jason Smith
• RET research funding made possible by the
  National Science Foundation (NSF)
• Morse Group Funding The Defense Advanced
  Research Projects
• Agency (DARPA) and The Department of Energy
  (DOE)

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Purpose

• To create stable, crystalline films of indium
  oxide
• To attain tunable levels of chromium doping
• Basic research

T.Tomita, K.Yamashita and J.Yasui and Y.Hayafuji,
Electronic Structures of Indium Oxide with
Point Defects and Bull.Soc.Discrete Variational
Xa, 16, O-2p09 (2003) (in press).
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Potential Applicationsbeyond basic research

• Memory devices and spin valves in the new
  frontier of spintronics
• Semiconductors
• Multiferroics
• The unknown . .

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What is a chromium doped indium hydroxide thin
film?

• It is just that. A thin film (thickness not yet
  determined )
• Forms on surface of aqueous solution given proper
  precursors and catalysts.
• Somewhat resembles a lily leaf (no scientific
  relevance) in shape, color and location
• ( floating on aqueous solution).

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Doping

• Film framework (base material) is indium
  hydroxide
• Doping substitution
• chromium is substituted for indium (see
  schematic)
• May result in unique electrical and magnetic
  properties
• Annealing (heating) film may result in
  crystalline structure of indium oxide doped with
  chromium, the desired result

Un-doped indium hydroxide
Doped
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Doping

• A brief animation

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Lingo

• X-ray diffraction XRD
• Scanning electron microscopy SEM
• Energy dispersive spectroscopy EDS
• Inductively coupled plasma spectroscopy ICP
• Carbon, hydrogen, nitrogen, analysis CHN
• Indium nitrate hydrate In(NO3)3XH2O
• Chromium III nitrate Cr(NO3) 3
• Ammonium hydroxide NH4OH

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Materials and MethodsGeneral Overview

• indium nitrate hydrate, and the dopant chromium
  III nitrate, are added to top and bottom rows of
  wells of 12 well reaction plate (noted IC)

Remove films from wells, whole films are
washed, powders are filtered
Well plate placed in covered reaction box, over
several hours thin films form
Whole films analyzed by SEM/EDS for
structure, elemental composition and
chromium incorporation
Powders/ film fragments analyzed by XRD
for crystallinity
solution of ammonium hydroxide (noted N), is
added to middle wells
CHN analysis
ICP analysis
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Materials and Methods

• A 2nd brief animation

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X-ray diffraction of thin film nanoparticles with
varying Cr doping levels
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8
6
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2
0

• XRD Utilized as a method for determining
  crystallinity
• Peak at (222?) corresponding to d spacing of
  4.04 Å, indium
• hydroxides most intensely scattering lattice
  plane
• sharp peak indicates crystallinity, higher
  doping (10)
• results in amorphous background signal no
  sharp crystalline peak

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EDS Data Overview In Conjunction With
Qualitative Data

• Low doping ( 2-4) macroscopically thin,
  brittle, films, predictable doping
• High doping ( 10) macroscopically thick,
  stable films, unpredictable doping
• 6 Cr doping consistent film stability and
  dopant incorporation, averaged 5.17 at (twelve
  experiments, forty-four data sets), candidate for
  further analysis

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Lessons Learned

• I learned that a thorough understanding only
  comes with thorough and complete analysis
• I learned the importance of accuracy and
  attention to detail
• I learned that patience is a virtue necessary for
  basic research
• Peer reviews can be painful but enlightening

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Special Thank You

• To Dr. Martina Michenfelder for her endless
  patience and wisdom
• To the staff of the MRL for making and creating
  such an outstanding opportunity for teachers
• To the NSF for continuing its dedication to
  support science and exploration
• To the Morse Group for a glimpse into biomimetic
  chemistry

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Preliminary Conclusion

• Indium hydroxide thin film chromium doping/
• incorporation can be influenced by adjusting
  chromium levels of starting solution

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Resources

• Indium oxide structure
• (image 1)
• T.Tomita, K.Yamashita and J.Yasui and
  Y.Hayafuji, Electronic Structures of Indium
  Oxide with Point Defects and Bull.Soc.Discrete
  Variational Xa, 16, O-2p09 (2003) (in press).
• Lily image courtesy of http//www.pirateplanet.com
  /