Intermetallic nanoparticles: synthesis and characterization

141 Pages·2006·5.22 MB·English

ETH Library
Intermetallic nanoparticles:
synthesis and characterization
Doctoral Thesis
Author(s):
Pigozzi, Giancarlo
Publication date:
2006
Permanent link:
https://doi.org/10.3929/ethz-a-005188057
Rights / license:
In Copyright - Non-Commercial Use Permitted
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Diss. ETH No. 16552
Intermetallic nanoparticles:
synthesis and characterization
Giancarlo Pigozzi
Zurich, 2006

Diss. ETH No. 16552
Intermetallic nanoparticles:
synthesis and characterization
Adissertationsubmittedto the
SWISSFEDERALINSTITUTE OFTECHNOLOGYZURICH
forthe degreeof
DOCTOROFSCIENCES
presentedby
Giancarlo Pigozzi
Dipl. Phys.,UniversitàdegliStudidiMilano,Italy
born onMarch10th,1978
citizen ofItaly
Acceptedon therecommendationof
Prof. Dr. G.Kostorz,examiner
Prof. Dr. R. Spolenak,co-examiner
Dr. D.Mukherji,co-examiner
Zurich, 2006

ALuisa,
lavocedei mieisogni.
Ai mieigenitori.
AFlora,
volatavia conla
neved’inverno.

Consideratela vostrasemenza:
fatti nonfostea vivercomebruti,
ma perseguirvirtuteecanoscenza.
-DanteAlighieri,Inferno XXVI-
(cid:127)
Science is built up with facts, as a house is with
stones. Butacollectionoffactsisnomoreascience
thana heapof stonesisa house.
Thescientistdoesnotstudynaturebecauseitisuse-
ful; he studies it because he delights in it, and he
delights in it because it is beautiful. If nature were
not beautiful, it would not be worth knowing, and
if nature were not worth knowing, life would not be
worthliving.
-J. H.Poincaré-
(cid:127)
Wer mit Ungeheuern kämpft, mag zusehn, dass er
nicht dabei zum Ungeheuer wird. Und wenn du
lange in einen Abgrund blickst, blickt der Abgrund
auchindichhinein.
-F.W.Nietzsche,JenseitsvonGut undBöse-

Contents
Abbreviations andsymbols v
Summary vii
Riassunto ix
1 Introduction 1
2 Nanoparticles andtheir properties 3
2.1 Generalaspects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.1.1 Increasedratioofsurface tovolume . . . . . . . . . . . . . . . . . . . 3
2.1.2 Surface structurechanges . . . . . . . . . . . . . . . . . . . . . . . . 4
2.1.3 Electronic properties . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.1.4 Optical properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.1.5 Magnetic properties . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.1.6 Catalyticproperties . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.2 Typesofnanoparticles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.2.1 Metallicnanoparticles . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.2.2 Intermetallicnanoparticles . . . . . . . . . . . . . . . . . . . . . . . . 8
2.2.3 Core-shellnanoparticles . . . . . . . . . . . . . . . . . . . . . . . . . 9
3 Preparation ofnanoparticles 11
3.1 Metallicandintermetallicnanoparticlesynthesis . . . . . . . . . . . . . . . . . 11
3.1.1 Existingmethods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
3.1.2 Electrochemicalmethodofintermetallicnanoparticlepreparation . . . 12
3.2 Suitablealloysystems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.2.1 Alloycompositionandheattreatment . . . . . . . . . . . . . . . . . . 12
3.2.2 Precipitatesize . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
3.2.3 Precipitatemorphology . . . . . . . . . . . . . . . . . . . . . . . . . . 14
3.3 Electrochemistryofanodicdissolutionofmetals . . . . . . . . . . . . . . . . . 15
3.3.1 Dissolutionofpuremetals . . . . . . . . . . . . . . . . . . . . . . . . 15
3.3.2 Dissolutionofalloys(single-phase) . . . . . . . . . . . . . . . . . . . 19
3.3.3 Dissolutionofalloys(twophases) . . . . . . . . . . . . . . . . . . . . 21
3.4 Electrochemicalbehaviorofbinary andternary Ni-Al-Sialloys . . . . . . . . . 23
3.4.1 Thebulkalloysystem . . . . . . . . . . . . . . . . . . . . . . . . . . 23
3.4.2 Experimentaldetails . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
i