conférence Karlovy Vary

Study ofsome gilded film/glass interfacesand ofone standard type of “liquid gold”

XVI ICF TECHNICAL EXCHANGE CONFERENCE

9th-12th October 2004

Karlovy Vary

Evelyne Darque-Ceretti, Doriane Hélary, Virginie Deram

Ecole des Mines de Paris

Centre de Mise en Forme des Matériaux

UMR CNRS 7635

Sophia-Antipolis

France

XIV Technical Exchange Conference Waterford, Ireland

October 12 th – 14 th 2002

Annette Lukas/ Ceramic Colour Division Heraeus Germany

Composition of precious metal preparations

Introduction

Thin gilded films from organo-metallic solutions are used todecorate glass objects

Organo-metallic solution = “liquid gold”

Objectives:

1.Analysis of interactions after firing

between gold and glass, (treated or no)

2. Characterization of another type of “liquid gold”

before and during firing

Part 1: Gilded film /glass

Specimen

Characterization methods

Surfaces observation

Interfacial reactions

Conclusions

Specimen

soda-lime glass

untreated

treated with a Ti oxide film (~ 6 nm thick)

or a Sn oxide film (~ 8 nm thick)

- organometallic preparation with 12 % ofmetallic Au + small metal additions (Rh, Ag, V, Zr …)

- deposition on the substrate and firing in air at~ 600°C during 15 min

~ 0.1-0.2 µm thick

Substrates

Gold films

Characterisation methods - Why use them ?

Scanning Electron Microscope (SEM)

morphology (SE mode) and atomic contrast (BSEmode) of the specimen surfaces

Secondary Ion Mass Spectrometry (SIMS)

Depth distribution of elements (C, Au, Ti, Si, …) withgreat sensitivity but problems due to charge effectsin the glass substrate

Glow Discharge Optical Emission Spectrometry (GDOES)with radio frequency

Depth distribution for all elements without chargeeffects

SEM surfaces observation

ä Non continuous golddistribution

ä Formation of an agglomeratedstructure

BSE mode

SE mode

ä Rough surface

Ra ~ 0.4 µm

For all specimen surfaces :

Sn treated glass

Firing temperature 600°C

Interfacial reactions

Glass substrate

Intermediate zone

Film ~ 0.2 µm

197 Au (*50)

12 C (*1000)

28 Si (*100)

107 Ag (*1000)

120 Sn (*1000)

Chargeeffects

SIMS analysis :

In negative secondary mode

Sn treated glass

- Gold diffusion into the substrates

- Tin diffusion preferentially into the gilded film

- Contamination by hydrocarbons (C)

- Silicon diffusion to the surface

Interfacial reactions

Distribution of Au diffused into Sn or Ti

treated or untreated glass at 600°C

Fitting by the second Fick’s law :

Au diffusion until 0.15 µm

Quite the same DAu for Ti or Sn pre-treated glassat 600 °C :

D Au treated glass  2.4 10-14 cm2/s

Ti pre-treated

DAu untreated glass  4 10-13 cm2/s

Au diffusion until 0.75 µm

0,00

0,03

0,05

0,08

0,10

0,13

0,15

0,18

0,20

0,23

0,25

Distance from interlayer/glass interface (µm)

Normalised intensity

Ti,Sn

Gold diffuses faster into untreated glass

Intermediate oxide layer = diffusion barrier

Au diffusion until 0.15 µm

Ti treated glass

Glass substrate

Film

~ 0.2 µm

Intermediate

zone

- Migration of alkali constituents of the base glass in the film with

segregation at the extreme surface

- Gold diffusion into the substrates

-Titanium diffusion preferentially into the gilded film

- Contamination by hydrocarbons (H)

- Oxidation of the gilded layer (due to the thermal treatment in air)

Ca/2

Au*2

K*2

Film

~ 0.2 µm

Intermediate

zone

Glass substrate

Rf-GDOES analysis :

Interfacial reactions

Conclusions

- For (600°C) faster Au diffusion into untreated glassDAu  4 10-13 cm2/s than pre-treated glass DAu  2.4 10-14cm2/s

Ti and Sn interlayers act as a diffusion barrier

- Ti and Sn diffusion into the gold film and into the glass

formation of compounds Au-Ti or Au-Sn ?

- Diffusion of alkali components from the glass into thegold film

formation of compounds ?

- Substantial presence of O in the gilded zone

formation of a gold oxide ?

Part 2: Characterization of a “liquid-gold”

Specimen

In-situ observations and analyses during the heatingprocess

Conclusions

Our liquid gold

Solid resin

in situ analytical methods

Optical microscope, X-ray diffraction, and thermal methods(differential scanning calorimeter and gravimetric analysis)

Sequential methods

Scanning electron microscope, energy dispersive spectrometryFTIR spectroscopy

500m

1 mm

25°C

1 mm

25°C

1 mm

65°C

1 mm

65°C

1 mm

350°C

1 mm

350°C

1 mm

450°C

1 mm

450°C

1 mm

600°C

1 mm

600°C

1 mm

200°C

1 mm

200°C

Optical Microscope + Thermo-Gravimetric Analysis

Metallic film formationsmoothing, spreading

Drying phase

Evaporation ofthe solvent mix

Thermal decompositionof the resinates

Reflectance FTIR

25°C - 150°C :

Loss ofhydrocarbons

150°C - 330°C :

 C=O vibrationDecompositionof R-SO2-OR'groups

Above 350°C :

Thin filmformation

C-Hvibration

C=Ovibration

R-SO2-OR'groups

Transmittance

300°C  650°C

 FWHM

Increase of goldcrystallite size

300°C

Crystalline gold

Amorphousresins

X-Ray diffraction

Complementary analysis : EDS

Surface analysis after firing

HEATING

Liquid gold after screen-printing

Thickness  50 m

600°C : Heterogeneous film

Thickness  150 nm

Conclusions

- Critical temperature 300°C

Existence of the first gold crystallites

- From 300°C to 600°C,

Gold recrystallisation and grain growth

Oxidation or decomposition of some componds :V,Rh?Smoothing and spreading of the film

Interdiffusion of gold into the glass and alkalielements into the gilded film (part 1)

What is the effect on adhesion properties?