Project 9 (Oviedo University)

Title: New applications of continuous and pulsed RF-GD-OES for the analysis of advanced materials

Researcher: Deborah Alberts (ESR)

Coordinator: University of Oviedo, Chemistry Department 

Reponsible Scientist: Rosario Pereiro

Other partners: EMPA, CUFR Albi, KIMAB

State of the art

Most of the exploratory studies on pulsed Glow Discharges have been carried out with pulsed dc-GDs. However, pulsed dc-GDs can be used just for the direct analysis of conductors and semiconductors and this has limited its interest (there is no commercial equipments available). Pulsed rf-GDs coupled to Optical Emission Spectrometers are almost analytically unexplored. However, in this case the potential of application is very high since they allow the analysis of insulating samples (for which the problems related to thermal effects become particularly critical). Very recently a pulsed rf-GD-OES instrument has been marketed by Horiba Jobin Yvon; however it uses continuous detection by photomultiplier tubes and does not allow temporal discrimination in the OES data acquisition.

About the Project

Objective and Innovation:

In this project, analytical applications of pulsed rf-GD-OES with and without time discrimination in the data acquisition system compared. There will be particular stress on the development of quantification methods of non-conducting materials and the quantification of light elements. Examples of the types of materials of present technological importance that will be investigated in this project, as pulsed rf-GDs should solve analytical problems now encountered with continuous rf-GD sources:

Nanostructured materials such as nanotubes, either empty or filled (totally or partially) with metals such as Ni, Fe, Co (magnetic nanowires).

Polymers and other thermally unstable samples. Many plastics contain elements that play significant roles in their functions, such as bromine and chlorine in flame retardants, zinc in antimicrobials and titanium in white pigments.

Impurities in silicon. Investigate the performance of the pulsed rf-GD in terms of sensitivity for the analysis of semiconductors up to a purification stage of solar grade silicon.

The reason why to use pulsed rf-GD-OES instead of the better known continuous rf-GD-OES is of the following important analytical advantages

• The possibility to discriminate analytical signals using time gated detection.
• The high peaks of power increase during the process gives rise to a sensitivity increase.
• There are less problems derived from thermal effects, due to less average power used
• A better depth resolution for the analysis of thin films because of the lower average sputtering.

The possibilities offered by the temporal and spatial distribution of atoms and ions can be easily used when the detection is carried out by mass spectrometry because in MS detection is directly involved the mass transport. However, it also possible to exploit the temporal dependence in the production of excited atoms when photons are detected. In the case of pulsed dc-GDs it has been observed that photons from the discharge gas emission can be detected from instants very close to the pulse generation, however the emission from the sample atoms arises several microseconds afterwards because these atoms have to be first sputtered. Therefore, with an optical detection system able to carry out time resolved measurements, it could be possible to obtain spectra of the analytes minimising the signals from interferences.

Because of these advantages and the almost unexplored field of pulsed rf-GD-OES, the potential of this application is very high since they furthermore allow the analysis of insulating samples.

So in this project, analytical applications of pulsed rf-GD-OES with and without time discrimination in the data acquisition system will be compared. There will be particular stress on the development of quantification methods of non-conducting materials and the quantification of light elements. 

Posters and Presentations

Deborah presented first results of her research on the application of pulsed glow discharges in an invited talk at the 4th international GD-Day at Horiba Jobin Yvon, France, September 2008.

Her work was also presented on a poster

1. D.Alberts, J.Pisonero, R.Pereiro, N.Bordel, A.Sanz-Medel; "Descargas luminiscentes pulsadas acopladas a espectrometria de emision optica y de masas por el analisis de nanocapas" JAI, 12th conference on instrumental analysis, Barcelona, Spain, 21-23th October 2008
2. Beatriz Fernandez, Deborah Alberts, Myrian Fernandez, Nerea Bordel, Rosario Pereiro, Alfredo Sanz-Medel; "Pros and cons of pulsing radiofrequency glow discharges coupled to optical emission spectrometry (rf-GD-OES) for depth profiling analysis"; Poster at European Winter Conference on Plasma Spectrochemistry 2009 Graz (Austria) 15-20 Febrero 2009
3. D. Alberts, P. Horvath, Th. Nelis, R. Pereiro, N. Bordel, J.A. Whitby, J. Michler, A. Sanz-Medel; "The measurement of pulsed emission profiles by radiofrequency glow discharge optical emission spectroscopy"; Oral presentation at Colloquium Spectroscopicum Internationale XXXV Budapest (Hungary); 30 august – 3 September 2009
4. D. Alberts, L. Therese, Ph. Guillot, R. Pereiro, N. Bordel, Ph. Belenguer, M. Ganciu; "Parametric study as a function of dimensions, with and without conductive layers, on electrical and optical characteristics of alumina samples by rf-GD-OES" Poster at Colloquium Spectroscopicum Internationale XXXV Budapest (Hungary); 30 august to 3 September 2009
5. B. Fernandez, D. Alberts, R. Pereiro, N. Bordel, A. Sanz-Medel; "Evaluation of pulsed radiofrequency glow discharge optical emission spectrometry (rf-GD-OES) for the depth profile analysis of conductive and insulator materials" Poster at Colloquium Spectroscopicum Internationale XXXV Budapest (Hungary); 30 august to 3 September 2009
6. D. Alberts, V. Vega, R. Pereiro, N. Bordel, V. M. Prida, A. Bengtson, A. Sanz-Medel; "Direct analysis of titanium and aluminium nanostructured layers by radiofrequency glow discharge coupled to optical emission spectroscopy"; Poster at III Workshop de nanociencia y nanotecnologia anali­tica, Oviedo (Spain); 16 - 18 September 2009
7. B. Fernandez, D. Alberts, R. Pereiro, N. Bordel, A. Sanz-Medel; "Evaluation of pulsed radiofrequency glow discharge optical emission spectrometry (rf-GD-OES) for the depth profile analysis of conductive and insulator materials"; Poster at III Workshop de nanociencia y nanotecnologia anali­tica, Oviedo (Spain); 16 - 18 September 2009
8. D. Alberts, V. Vega, R. Pereiro, N. Bordel, V. M. Prida, A. Bengtson, A. Sanz-Medel; " In-depth profile analysis of filled alumina and titania nanostructured templates by radiofrequency glow discharge coupled to optical emission spectrometry"; Anal. Bioanl Chem. ; 2009;  DOI: 10.1007/s00216-009-3327-2

Scientific publications related to this project:

1. V. Vega, M.A. Cerdeira, V.M. Prida, D. Alberts, N. Bordel, R. Pereiro, F. Mera, S. Garci­a, M. Hernandez-Valez and M. Vazquez; "Electrolyte influence on the anodic synthesis of TiO2 nanotube arrays";  Jounal of non-crystalline solids,  doi:10.1016/j.jnoncrysol.2008.05.073 
2. D.Alberts, P. Horvath, Th. Nelis, R. Pereiro, N. Bordel, J. Michler, A. Sanz-Medel; "Time resolved measurement of the Emission Pprofiles in Pulsed radiofrequency Glow Discharge Optical Emission Spectroscopy: Investigation of the Pre-peak"; Spect. Chem Acta B. ; accepted Mai 2010, DOI
3. D.Alberts, P. Horvath, Th. Nelis, R. Pereiro, N. Bordel, J. Michler, A. Sanz-Medel; "Time resolved measurement of the Emission Pprofiles in Pulsed radiofrequency Glow Discharge Optical Emission Spectroscopy: Investigation of the Pre-peak"; Spect. Chem Acta B. ; accepted Mai 2010, DOI

Future contribution:

Autores : D. Alberts, V. Vega, R. Pereiro, N. Bordel, V. M. Prida, A. Bengtson, A. Sanz-Medel

Título: Comparison of continuous and pulsed  radiofrequency glow discharge coupled to optical emission spectroscopy for the direct analysis of  nanostructured layers by

Tipo de participación: Poster

Congreso: Winter Plasma Conference 2010

Lugar celebración: Florida (USA)    Fecha: 3 -8 January 2010

Autores: D. Alberts, L. Therese, Ph. Guillot, R. Pereiro, N. Bordel, Ph. Belenguer, M. Ganciu

Título: Electrical and optical characteristics of Al2O3 samples analysed rf-GD-OES with and without magnetic field

 Tipo de participación: Poster

Congreso: Winter Plasma Conference 2010

Lugar celebración: Florida (USA)    Fecha: 3 -8 January 2010

Some information about Asturias:

The Principality of Asturias is one of the 17 self-governing communities constitutionally forming the Kingdom of Spain. It is situated in the North, on one side its coastline and on the other the Cantabrian Mountain range. Together with Galicia, Cantabria and the Basque country it forms the Cornisa Cantábrica, which is also known as «the Green Spain».The climate is basically an Atlantic one with mild temperatures and abundant rainfall all the year round which favours the existence of varied and rich vegetation (such as the Forest of Muniellos and the National Park of Covadonga), and an important hydrographic system formed by fast-running abundant rivers (such as the Nalón, the Navia, the Deva and the Sella), and lakes and lagoons of great beauty (for example those of Covadonga and Saliencia).
The territory is uneven and three different areas can be distinguished. First,an area of high mountains within the Cantabrian system where the Peaks of Europe rise to great heights, such as Torre Cerredo (2,646 metres), and the mythical Naranjo de Bulnes (2,519 metres). A second area is one of inland sierras, narrow valleys, meadows and woodland descending from the mountains to the coasts and the littoral area which is rocky with numerous cliffs, beautiful beaches and river estuaries (such as those of Llanes, Villaviciosa and Ribadesella).
The origins of Asturian culture date back to prehistory, as witnessed by. prehistoric cave paintings (in the caves of Tito Bustillo and Candamo).Some of the most outstanding historical landmarks are the Roman thermal baths and other remains (in Gijón), Celtic forts (as in Coaña), pre-Romanesque monuments characterized by their own particular style (for example, the churches of Santa María del Naranco, San Miguel de Lillo, San Julián de los Prados and Santa Cristina de Lena), monuments of Romanesque art (like the monasterio de San Salvador de Cornellana and Santa María de Valdediós), and also of Gothic art (the Cathedral of Oviedo).

Asturias has a population of nearly one million, one hundred thousand inhabitants unevenly distributed throughout its seventy-eight councils. Of these,
Gijón, Oviedo and Avilés are the most densely populated. The city of Oviedo is situated in central Asturias at the foot of the Naranco
sierra combining a prosperous urban area with a monumental heritage which bears witness to a past rich in history. Oviedo is the capital of the Principality
and the political, administrative, cultural and commercial centre of the region. Most University centres are located in Oviedo.
Gijón, situated midway along the length of the Asturian coast, is the largest city in the Principality. Though dynamic and progressive it is a city with an easygoing atmosphere. It is also an industrial and services city, with industrial andrecreational ports, five beaches and sporting facilities. It is home to many museums and offers many cultural opportunities. Some of the University centres are located in Gijón.
Avilés, Mieres and Cangas de Onís, Sama de Langreo, La Felguera and Pola de Laviana are some of the other most important centres of the region.
The beauty of the natural features of the region and its wealth of historical, cultural and artistic traditions draw visitors to Asturias. However, the people of
Asturias, known for their hospitality, friendliness and dynamism together with their lively music and dances, fi estas, fairs and celebrations make Asturias an
attractive part of Spain to visit.

The texte is extracted from the "Guide for international students" written in an effort to help foreign students integrating in their new environment.