slide1 n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Soft chemical synthesis of nanomaterials: PowerPoint Presentation
Download Presentation
Soft chemical synthesis of nanomaterials:

Loading in 2 Seconds...

play fullscreen
1 / 28

Soft chemical synthesis of nanomaterials: - PowerPoint PPT Presentation


  • 155 Views
  • Uploaded on

IMNR. Soft chemical synthesis of nanomaterials: challenges for technology transfer in electronic applications. Radu R. Piticescu, Roxana M. Piticescu, National R&D Institute for Non-Ferrous and Rare Metals, Pantelimon, Ilfov, ROMANIA. Presentation content. Introduction

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Soft chemical synthesis of nanomaterials:' - ivana-calhoun


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
slide1

IMNR

Soft chemical synthesis of nanomaterials:

challenges for technology transfer in electronic applications

Radu R. Piticescu,Roxana M. Piticescu,

National R&D Institute for Non-Ferrous and Rare Metals,

Pantelimon, Ilfov, ROMANIA

Al 5-lea Seminar "Nano" 2 martie 2006

slide2

Presentation content

  • Introduction
  • Problems and barriers in development and applications of hydrothermal procedures for electronic materials
  • Applications in BST ceramics
  • Applications in Al-doped ZnO
  • Conclusions and future works

Al 5-lea Seminar "Nano" 2 martie 2006

slide3

Nanomaterials market: 490 billion dollars in 2004 and 900 billion dollars in 2005 and 11 trillion dollars in 2010 (annual average grown rate > 10%)

The primary of nanomaterials companies material product types and primary market focuses of nanomaterials companies

INTRODUCTION

Nanomaterials – the driving force, by Michael J. Pitkethly, Market Report, December 2004.

Al 5-lea Seminar "Nano" 2 martie 2006

slide4

Hydrothermal reactions: chemical processes at high pressures and temperatures over the boiling temperature in aqueous solutions

Solvothermal reactions: chemical processes at high pressures and temperatures in non-aqueous solutions

Hydrothermal reactions between species in hydrothermal solutions

One element

M(II)2+(aq) + 2OH-(aq) = MO+H2O; M(II)=alcaline-earth metals: Mg, Ca, Sr, Ba

2M(III)3+(aq) + 6OH-(aq) = M2 O3 + 3H2O; M(III)= Al, Ga, Ln

M(IV)4+(aq) + 4OH-(aq) = M O2 + 2H2O; M(IV)= Si, Ge, Ti, Zr, Hf, Mn,...

Two elements (ABO3, ABO4,....compounds)

xM(II)2+(aq) +y M(IV)4+(aq) +6(x+y)OH-(aq) = M(II)xM(IVy)O3 + 3(x+y)H2O;

xM(III)3+(aq) + yM’(III)3+(aq) +6(x+y)OH-(aq) =

xM(III)2 yM’(III)2 O3(x+y) + 3(x+y)H2O

Hydrothermal crystallisation: transformation of amorphous species in crystalline ones (under the influence of temperature and pressure):

M(OH)n = MOn/2 +(n/2) H2O

INTRODUCTION

Al 5-lea Seminar "Nano" 2 martie 2006

slide5

M.Yoshimura, W.Suchanek, Solid State Ionics 98 (1997), pp. 197-208

Problems and barriers in development and applications

of hydrothermal procedures for electronic materials

  • STRENGTHS OF HYDROTHERMAL SYNTHESIS
  • One step process
  • Minimize energy consumption
  • Closed systems, low environmental impact
  • Products with much higher homogeneity than solid state processing

Al 5-lea Seminar "Nano" 2 martie 2006

slide6

U/I

Hydrothermal deposition

PT; PZ; ST; BT

Electrophoretic deposition

PT; PZ; ST; BT

Cathode

Reference

Anode

Problems and barriers in development and applications

of hydrothermal procedures for electronic materials

STRENGTHS OF HYDROTHERMAL SYNTHESIS

Any shape, any size (combining with other external driving forces, e.g. electrochemical)

R.R. Piticescu, R.M. Piticescu, Workshop COST D30, Turin, 26-28 Feb. 2004

Al 5-lea Seminar "Nano" 2 martie 2006

slide7

log Ai= Hi +BZi + Pi

Ji is the stoechiometric coefficient of species “i” in the reaction “j”

G0f is the standard free enthalpy of formation of reacting species AJi

mAi is the molar concentration of species Ai the solution

i is the activity coefficient

Lencka and Riman (Rutgers Univ), J.Am.Ceram.Soc, 76, 10, 2649-59 (1993)

Problems and barriers in development and applications

of hydrothermal procedures for electronic materials

  • WEAKNESSES
  • Prediction: Lack of thermodynamic data (only for ideal solutions, low valence ions)

Al 5-lea Seminar "Nano" 2 martie 2006

slide8

125C

150C

-ln (1-)= kt m

200C

Problems and barriers in development and applications

of hydrothermal procedures for electronic materials

  • WEAKNESSES
  • Prediction: Kinetic limitations

Roxana M. Piticescu, R. R. Piticescu, D.Taloi, V. Badilita, Nanotechnology vol. 14 (3), pp. 312-17 (2003)

R.R. Piticescu, C. Monty, D. Taloi, D. Millers, Sensor and Actuators B, 109 (1), 102-6 (2005)

Al 5-lea Seminar "Nano" 2 martie 2006

slide9

Problems and barriers in development and applications

of hydrothermal procedures for electronic materials

OPPORTUNITIES

VERSATILITY:Oxides, non-oxides, organic/biologic materials; hybrid materials

HYDROTHERMAL SYNHTESIS IS ONE OF THE VERY FEW METHODS ABLE

TO GENERATE NEW MATERIALS OR MATERIALS WITH RADICALLY NEW PROPERTIES

Recent examples: new ultra-hard materials (e.g. BC2N)[1] some of which can be doped for semiconductor (e.g. p- and n- doped cubic-BN)[2] or opto-electronic (e.g. cubic-Si3N4)[3] applications,. ANi3+0.98Fe0.02O3 (A=Nd, Lu) perovskites[4] New physical phenomena may be found, for example the perovskite BiNiO3 (prepared at 60 kbar, 1000 °C) shows a unique transition between a metallic state, with charge distribution Bi3+Ni3+O3, and a valence disproportionated and charge ordered insulating state, Bi3+Bi5+(Ni2+)2O6.[5]

[1]Solozhenko,V. L., Dub, S. N. & Novikov, N. Diamond Relat.Mater. 10, 2228–2231 (2001)

[2]Taniguchi, T. et al. Jpn. J.Appl. Phys. 241, L109–L111 (2002).

[3]I.A.Presniakov, G.Demazeau, A.V.Baranov, A.V.Sobolev, K.V.Pokholok., Phys. Rev. B71, 2005, 054409

[4]Gryko, J. et al. Phys. Rev. B 62, 7707–7710 (2000).

[5] Ishiwata S, Azuma M, Takano M, et al, J. Mater. Chem. 12, 3733 (2002).

Al 5-lea Seminar "Nano" 2 martie 2006

slide10

Nucleation and growth

  • surface diffusion
  • continuous growth at the kinks
  • Formation of clusters and critical nuclei
  • Formation of monolayrers by layer to layer growth

W(t) = W0 ( 1 - ekt )

Types of morphologies

  • Layer or platelate growth
  • Pyramidal growth
  • Whiskeres
  • Dendrites
  • Epitaxial growth on crystalline substrates
  • Oriented growth on polycrystalline or amoprphous substrates

Unpredictible!

Problems and barriers in development and applications

of hydrothermal procedures for electronic materials

Al 5-lea Seminar "Nano" 2 martie 2006

slide11

THREATS

Phase separation: additives for agglomeration/de-agglomeration (steric or electrostatic effects)

Processing: fine, nanocrystalline powders require high pressures to be compacted special forming technologies

elastomer

fluid

+kT

V repulsion

V total

Vt

H

-kT

V atraction

Problems and barriers in development and applications

of hydrothermal procedures for electronic materials

lack of reliable and standardised characterisation methods;

anxiety of end-users vis-à-vis of environmental problems related to nanopowders manipulation

Al 5-lea Seminar "Nano" 2 martie 2006

center of technological transfer for advanced materials
Center of Technological Transfer for Advanced Materials
  • Identify market requirements for new technologies, services and products in the field of advanced biocompatible and smart metallic, ceramic and composite materials;
  • Consultancy and expertise in the field of advanced materials;
  • Participation in elaboration of prognoses in the field;
  • Encouraging specialized studies for students, masters, PhD students;
  • Consultancy for SMEs and companies in the elaboration and participation in national and European R&D projects;
  • Support for SMEs in implementation of European standards for materials

Al 5-lea Seminar "Nano" 2 martie 2006

slide13

HT synthesis 150 0C/3h; sintering 1250 0C

HT synthesis 200 0C/3h; sintering 1250 0C

Applications: hydrothermal synthesis of BST

Dielectric, piezoelectric and electro-optic properties for applications in the electronic industry: imaging devices, optical memories, modulators, transducers, actuators, high-k dielectric constant materials. Properties strongly dependent on the metallic elemental ratios, impurities, microstructure and grain sizes.

Al 5-lea Seminar "Nano" 2 martie 2006

slide14

Non-stoichiometric; sintering 1250 0C

Stoichiometric composition

Nanodomains?

A

Applications: hydrothermal synthesis of BST

Al 5-lea Seminar "Nano" 2 martie 2006

slide15

Cathodo-luminescence spectrum (electron beam excitation) with different delay times

Fundamental absorption

Applications: hydrothermal synthesis of BST

Al 5-lea Seminar "Nano" 2 martie 2006

slide16

= (C*d)/(0*S)

0=8.85 810-12 farad/m,

C-capacity, farad

d-thickness, m

S-surface area, m2

Applications: hydrothermal synthesis of BST

Al 5-lea Seminar "Nano" 2 martie 2006

slide17

Applications: synthesis of Al-doped ZnO

  • Non-stoichiometric (Zn1+xO)
  • Semi-conducting transparent oxide with a large band gap (3.4eV). Doping with impurities such as Al and In can increase the conductivity of ZnO (large values of electronic carrier density: n~1020cm-3, and mobility: n ~ 1000 cm2V-1).
  • Piezoelectric properties of zinc oxide thin films can be used in various transducers, acoustic wave and acoustic-optical devices.
  • Combination of high visible transparency and low electrical resistivity is very useful in applications such as transparent electrodes in solar cells, luminescence display screens, ultraviolet diodes .
  • When ZnO is in polycrystalline form, luminescence depends on the grain size; ZnO nanomaterials offer from this point of view a new and promising field of investigations.

Exciton type and donor-acceptor

luminescence

Deffect associated luminescence

Al 5-lea Seminar "Nano" 2 martie 2006

slide18

0.1 % Al ZnO- hydrothermal precursor

0.1 % Al ZnO vc5- solar furnace

Applications: synthesis of Al-doped ZnO

R.R. Piticescu, R.M. Piticescu, C. Monty, L. Grjgorieva (under press in J.Eur.Ceram.Soc. 2006)

Al 5-lea Seminar "Nano" 2 martie 2006

slide19

0.5 Al% ZnO hydrothermal precursor

0.5 Al% ZnO vc10- solar furnace

Applications: synthesis of Al-doped ZnO

Al 5-lea Seminar "Nano" 2 martie 2006

slide20

Applications: synthesis of Al-doped ZnO

Al 5-lea Seminar "Nano" 2 martie 2006

slide21

[0002]

[0002]

[0002]

[1010]

[1011]

[1011]

[1010]

[1010]

[1011]

Applications: synthesis of Al-doped ZnO

Al 5-lea Seminar "Nano" 2 martie 2006

slide22

Applications: synthesis of Al-doped ZnO

Al 5-lea Seminar "Nano" 2 martie 2006

slide23

PL spectra: two bands – band edge emission (likely of free excitonic and band-to-band and free-to-bound origin) peaked at about 380 nm and a broad band emission (defect related band) peaking at about 520 nm to 600 nm. The broad PL band clearly is due to an overlap of two known ZnO defect related bands – ZnO red PL emission and ZnO green PL emission. The latter dominates in samples with a higher Al fraction. Further studies are required to get a better insight to origin of these two bands and in order to determine conditions of their observations. We noticed that band edge emission is red shifted in nanopowders, as compared to a spectral position of a relevant band in the reference sample.

Applications: synthesis of Al-doped ZnO

Al 5-lea Seminar "Nano" 2 martie 2006

slide24

UV-VIS spectra of 4Al ZnO films

Applications: synthesis of Al-doped ZnO

Pure and Al doped ZnO has been produced using the hydrothermal method. Lattice constant increased while the density decreases with an increase of Al content. Enhancement of luminescence with increase of Al content (related to a surface passivation or impurity-related defect reaction?) The morphology of the product varied strongly with the synthesis parameters.

The vaporisation-condensation technique in a solar reactor from hydrothermal precursors lead to a change of morphology and creation of whiskers. The so-obtained powders/whiskers show brighter light emission, even though the solubility limit of Al decreased comparing to the precursor made using the hydrothermal method.

Al 5-lea Seminar "Nano" 2 martie 2006

slide25

CONCLUSIONS

  • Hydrothermal synthesis is a versatile method for producing many nanomaterials with controlled stoichiometry and doping elements concentrations
  • Hydrothermal + electrochemical: producing of thin/thick films
  • Hydrothermal + PVD : increase dopant level of elements with low vapour pressure and control morphology
  • FUTURE PROSPECTS
  • BST nanomaterials (sintered pellets, thin films): study the role of nanodomains on PL spectra and electrical properties, modeling the device
  • Al-ZnO nanomaterials (p-type, powders and thin films): electro-optical properties
  • N-doped (n-type nanomaterials) ?

Al 5-lea Seminar "Nano" 2 martie 2006

slide26

Future prospects

Al 5-lea Seminar "Nano" 2 martie 2006

contact persons
CONTACT PERSONS
  • Dr.Teodor Velea, General Director

e-mail : tvelea@imnr.ro

  • Dr. Roxana Piticescu, Lab. Head

e-mail : roxana@imnr.ro

  • Dr. Robert Piticescu, Director Center for Technology Transfer in Advanced Materials

e-mail: rpiticescu@imnr.ro

  • Phone/fax : 0040-21-352.20.48 / 352.20.45 
  • Address: 102 Biruintei Blvd., Pantelimon, judet Ilfov, Romania

Al 5-lea Seminar "Nano" 2 martie 2006

slide28

Nanostructured Materials Group – INCDMNR Pantelimon

  • Dr. C;l;aude Monty –CNRS /PROMES France
  • Prof. Witold Lojkowski and Dr. Pielaszeck-UNIPRESS Warsaw
  • Dr. Larisa Grjgorieva and Dr. Vismants Zaulus– Inst.
  • Solid State Physics Riga
  • Dr. I. Sajin and Dr. M. Dragoman-Nat. Inst. Mycrotechnologies
  • Dr. Eugeniu Vasile – METAV CD Bucharest
  • dr. eng. Maria Giurginca – CNC-UPB, Bucharest

thank you

EGIDE France – supporting the ECO-Net “Fun-Nanos” project

Acknowledgements

Thank you for your attention !

Al 5-lea Seminar "Nano" 2 martie 2006