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27 July 2021 | Story Leonie Bolleurs | Photo UFS Photo Archive
Prof Hendrik Swart played a key role in the Department of Physics acquiring the PHI Quantes XPS system, the first in Africa and one of only 20 in the world.

The state-of-the-art equipment in the Department of Physics at the University of the Free State (UFS) differentiates this department from its competitors. Availability of the equipment makes it possible for researchers as well as students to deliver work that receives national and international recognition. 

Recently, the department acquired a PHI Quantes XPS system, the first in Africa and one of only 20 in the world. 

Creating better phosphor 

“The Quantes XPS system uses X-rays to determine the chemical composition of molecules on the surface of a sample. The system is unique in the sense that it also has an extra X-ray source that can determine the chemical state below the surface, which was not possible in the past.  This will help us to dictate the position of defects in our phosphor materials that will consequently enable us to create better phosphor for solid state lighting as well as solar cell applications,” explains Prof Hendrik Swart, Senior Professor in the Department of Physics, who also holds the SARChI Chair in Solid State Luminescent and Advanced Materials.

After he had the opportunity to observe the system in the factory in Chigasaki, Kanagawa, Japan, where he attended a conference, Prof Swart was very impressed by its performance. He discussed it with Prof Koos Terblans, Head of the department, and other colleagues, and started making plans to buy the system. 

When the department first bought the X-ray photoelectron spectroscopy (XPS) system in 2007/2008, it became the national facility on XPS measurements. Not only is this an upgrade of the XPS system bought 14 years ago, but the new system will enable the department to do more measurements. “The number of samples that we have to handle has just become too much for one system. The new system’s increased capacity for making measurements addresses this challenge and it also gives UFS scientists and postgraduate students more time to spend on fundamental measurements to develop research of a higher level,” says Prof Swart.

(The Quantes XPS system. Photo:Supplied)

Explaining about the measurements, Prof Swart says: “This advanced X-ray photoelectron spectroscopy (XPS) instrument has the capability to analyse the very small area that the user is interested in and a large area of the uniform sample surface. The two different types of X-ray sources – the hard X-ray source and the more conventional soft X-ray source – can be switched automatically, allowing users to analyse the same area and/or points of a sample. The PHI Quantes XPS system ensures the availability of superior features such as automatic analysis, automatic sample transfer, turnkey charge neutralisation, and advanced data processing.”

“This XPS instrument is designed to pioneer new methods and applications transcending conventional ideas of what is possible.”

Optimising efficiency of materials

Prof Swart says the Department of Physics, especially the Research Chair in Advanced and Luminescent Materials, is developing new high-technology materials on a daily basis. “It is very important to know the chemical composition and defect distribution of the materials in order to add value to the fabrication of these materials,” he adds.

“The distribution of these defects is vital for the efficiency of the phosphor materials. If we know where these defects are located, we can determine the mechanisms of the light output coming from these phosphors,” describes Prof Swart.

Research conducted as part of the Research Chair in Solid State Luminescent and Advanced Materials will benefit significantly from this new system.

(Prof Koos Terblans, Head of the Department of Physics next to the Quantes XPS system. Photo:Supplied) 

“We are currently concentrating on phosphors as sensors (temperature), light-emitting diodes (LEDs), and solar cells, where we optimise the efficiency and durability of these materials. Any new knowledge, which I believe the PHI Quantes XPS system will provide us, will help us to reach our goal much quicker,” he says. 

Apart from the positive impact on research, the PHI Quantes XPS system will also be a benefit to society in the long term. Improved LEDs can be used to save electricity, and better solar cells can help to generate electricity, to mention but two examples. 

News Archive

DF Malherbe Memorial Lecture
2005-05-19

DF Malherbe Memorial Lecture: Language and language activism in a time of transformation (summary)
Proff Hennie van Coller and Jaap Steyn

Language activism necessary for multilingualism
The awareness is growing that language activism will be needed to bring about a truly democratic multi-lingual society. What is quite clear is that a firm resolve must continuously resist the concentrated pressure on Afrikaans-medium schools (and universities) to allow themselves to be anglicised through becoming first parallel medium, then dual medium, and finally English medium institutions.

Proff Hennie van Coller and Jaap Steyn said this last night (Wednesday night) in the 24th DF Malherbe Memorial Lecture at the University of the Free State. Prof van Coller is head of the Department Afrikaans, Dutch, German and French at the UFS. Both are widely honoured for their contributions to Afrikaans and the promotion of Afrikaans.

They discussed three periods of transformation since 1902, and said about the current phase, which started in 1994:  “Besides all institutions and councils having to be representative of South Africa’s racial composition, places of education were required to open their doors. Quite rapidly this policy has had the result that schools and universities may be solely English medium, but not solely Afrikaans medium. Afrikaans medium institutions — if they claim the right to remain Afrikaans — are quickly branded racist, even though their student body may include all races.

“Education departments are presently exerting great pressure on Afrikaans medium schools to become double or parallel medium schools.  Parallel medium education is an equitable solution provided it can be sustained. Established parallel medium schools, such as Grey College in Bloemfontein, have catered even-handedly for English and Afrikaans speakers for decades. But the situation is different in the parallel medium (and still worse in the double medium) schools that spring up usually at the behest of a department of education.

“Afrikaans schools are converted almost over-night into parallel or dual medium schools without any additional personnel being provided. Depending on the social environment, a parallel medium school becomes reconstituted as a dual medium school on average in five to eight years, and dual medium school becomes an English-only school in two to three years. Some Afrikaans medium schools have become English medium in just three years.

“Though the Constitution recognises mono-lingual schools, officials in the provinces insist that Afrikaans schools become dual or parallel medium; English medium schools are left undisturbed. One must conclude that the tacit aim of the state is English as the sole official language, despite the lip-service paid to multi-lingualism, and the optimistic references to post-apartheid South Africa as a ‘rainbow’ nation.”

They said a recent study has shown that the 1 396 Afrikaans schools in the six provinces in 1993 have dwindled to 844. The fall off in the Free State is from 153 to 97; in the Western Cape from 759 to 564; in Gauteng from 274 to 155; in Mapumalanga from 90 to 3; in the North West from 82 to 13; and in Limpopo Province from 38 to 12.

They said the changes at universities, too, have been severe, as university staffs well know. Ten years ago there were five Afrikaans universities. Today there are none. The government demanded that all universities be open to all, which has meant that all universities have had to become English medium. And no additional funding was forthcoming for the changes. The government policy amounts to a language “tax” imposed on the Afrikaans community for using Afrikaans.

“Only when all schools (and universities) are English will the clamor cease. Academics and educationists are beginning to speak openly of forming pressure groups to save Afrikaans schools, and of using litigation as one of their methods. 59% of Afrikaans parents have said they would support strong action if Afrikaans were no longer a medium of instruction at schools.”

 

 


 

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