Basic OverviewBasic Overview Kinetically Controlled Vapor Diffusion Kinetically Controlled Vapor Diffusion

Synthesis Of Chromium Doped Synthesis Of Chromium Doped Indium Hydroxide Thin FilmsIndium Hydroxide Thin Films

Faculty Advisor:Faculty Advisor: Dr. Dan MorseDr. Dan Morse

Research Mentors: Research Mentors: Dr. Birgit Schwenzer, James NeilsonDr. Birgit Schwenzer, James Neilson

RET Advisor: RET Advisor: Dr. Martina MichenfelderDr. Martina Michenfelder

RET Participant: RET Participant: Jason SmithJason Smith

RET research funding made possible by the National Science Foundation RET research funding made possible by the National Science Foundation (NSF)(NSF)

Morse Group Funding: The Defense Advanced Research Projects Morse Group Funding: The Defense Advanced Research Projects Agency (DARPA) and The Department of Energy (DOE)Agency (DARPA) and The Department of Energy (DOE)

PurposePurpose

To create stable, To create stable, crystalline films of indium crystalline films of indium oxide oxide

To attain “tunable levels ” To attain “tunable levels ” of chromium dopingof chromium doping

Basic researchBasic research

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

Potential ApplicationsPotential Applicationsbeyond basic researchbeyond basic research

Memory devices and spin valves Memory devices and spin valves in the new frontier of in the new frontier of “spintronics”“spintronics”

SemiconductorsSemiconductors MultiferroicsMultiferroics The unknown . . The unknown . .

What is a chromium doped indium What is a chromium doped indium hydroxide thin film?hydroxide thin film?

It is just that. A thin film It is just that. A thin film (thickness not yet determined )(thickness not yet determined )

Forms on surface of aqueous Forms on surface of aqueous solution given proper solution given proper precursors and catalysts.precursors and catalysts.

Somewhat resembles a lily leaf Somewhat resembles a lily leaf (no scientific relevance) in (no scientific relevance) in shape, color and location* shape, color and location*

( *floating on aqueous ( *floating on aqueous solution). solution).

DopingDoping Film framework (base Film framework (base

material) is indium material) is indium hydroxide hydroxide

Doping = substitutionDoping = substitutionchromium is substituted for chromium is substituted for indium (see schematic)indium (see schematic)

May result in unique May result in unique electrical and magnetic electrical and magnetic propertiesproperties

Annealing (heating) film may Annealing (heating) film may result in crystalline structure result in crystalline structure of indium oxide doped with of indium oxide doped with chromium, the desired resultchromium, the desired result

Un-doped indium hydroxide

Doped

DopingDoping

A brief animationA brief animation

LingoLingo

X-ray diffractionX-ray diffraction XRDXRD

Scanning electron microscopyScanning electron microscopy SEM SEM

Energy dispersive spectroscopyEnergy dispersive spectroscopy EDS EDS

Inductively coupled plasma spectroscopyInductively coupled plasma spectroscopy ICPICP

Carbon, hydrogen, nitrogen, analysis Carbon, hydrogen, nitrogen, analysis CHNCHN

Indium nitrate hydrate Indium nitrate hydrate In(NOIn(NO33))33·XH·XH22OO

Chromium III nitrate Chromium III nitrate Cr(NOCr(NO33) ) 33

Ammonium hydroxideAmmonium hydroxide NHNH44OHOH

Materials and MethodsMaterials and MethodsGeneral OverviewGeneral Overview

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

Well plate placed in covered reaction box,over several hoursthin films form

Remove films from wells, whole films are “washed”, “powders” are filtered

Whole films analyzed by SEM/EDS for structure,elemental composition and % chromiumincorporation

Powders/ filmfragmentsanalyzed by XRD forcrystallinity

CHN analysis ICP analysis

solution of ammonium solution of ammonium hydroxide (noted N), hydroxide (noted N), is added to middle wells

Materials and MethodsMaterials and Methods

A 2A 2ndnd brief animation brief animation

X-ray diffraction of X-ray diffraction of thin film thin film

nanoparticles with nanoparticles with varying Cr doping varying Cr doping

levelslevels

• XRD: Utilized as a method for determining crystallinity

• Peak at (22°[2Ө]) corresponding to d spacing of 4.04 Å, indium hydroxide’s most intensely scattering lattice plane

• sharp peak indicates crystallinity, higher doping (10%) results in amorphous background signal no sharp crystalline peak

10%

8%

6%

4%

2%

0%

EDS Data OverviewEDS Data Overview

In Conjunction With Qualitative In Conjunction With Qualitative DataData

• 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

Chromium doping incorporation in indium hydroxide thin films at varying doping levels

0

2

4

6

8

10

12

14

0 2 4 6 8 10 12

Theoretical Cr Incorporation

Ac

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l C

r In

co

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rati

on

Series1

Lessons LearnedLessons Learned

I learned that a thorough I learned that a thorough understanding only understanding only comes with thorough comes with thorough and complete analysis and complete analysis

I learned the importance I learned the importance of accuracy and of accuracy and attention to detailattention to detail

I learned that patience is I learned that patience is a virtue necessary for a virtue necessary for

basic researchbasic research Peer reviews can be Peer reviews can be

painful but enlighteningpainful but enlightening

Special Thank YouSpecial Thank You

To Dr. Martina Michenfelder for her endless patience To Dr. Martina Michenfelder for her endless patience and wisdomand wisdom

To the staff of the MRL for making and creating such To the staff of the MRL for making and creating such an outstanding opportunity for teachersan outstanding opportunity for teachers

To the NSF for continuing its dedication to support To the NSF for continuing its dedication to support science and explorationscience and exploration

To the Morse Group for a glimpse into biomimetic To the Morse Group for a glimpse into biomimetic chemistrychemistry

Preliminary ConclusionPreliminary Conclusion

Indium hydroxide thin film Indium hydroxide thin film chromium doping/chromium doping/

incorporation can be incorporation can be influenced by adjusting influenced by adjusting chromium levels of starting chromium levels of starting solutionsolution

ResourcesResources

Indium oxide structure Indium oxide structure

(image 1) (image 1)

T.Tomita, T.Tomita, K.YamashitaK.Yamashita and J.Yasui and J.Yasui and Y.Hayafuji, “Electronic Structures and Y.Hayafuji, “Electronic Structures of Indium Oxide with Point Defects” of Indium Oxide with Point Defects” and Bull.Soc.Discrete Variational Xα, and Bull.Soc.Discrete Variational Xα, 1616, O-2p09 (2003) (in press)., O-2p09 (2003) (in press).

Lily image courtesy of Lily image courtesy of http://www.pirateplanet.com/http://www.pirateplanet.com/