Interview of Geoffrey Mwendwa, PhD student in physics at Wits

Can you introduce yourself?

Name:

My name is Geoffrey Mũtũa Mwendwa, a Kenyan national born and raised in Kavalũla area, Matisaa village in Mwingi West District, Kitui County.

I hold bachelor and master degrees of science in physics, both awarded by Maasai Mara University (Kenya) in 2016 and 2020, respectively. I am currently a PhD candidate in physics at the University of the Witwatersrand, Johannesburg, South Africa.

I was recruited in an academic staff development programme by Maasai Mara University (Kenya) in 2017 where I served as a Graduate Assistant (GA) in the Department of Mathematics and Physical Sciences until 2020. I was later promoted to Tutorial Fellow (TF) in 2021. When I complete my Ph.D. studies, I will continue with my career in teaching and research. I am now thinking of post-doctoral prospects.

My hobbies are gardening and storytelling. Foremost as a gardener, I enjoy spending time outdoors, getting my hands dirty, and watching plants grow and thrive under my care. This is one of my childhood hobbies that has remained alive until to date. I was inspired by the need for soil conservation and irrigation in semi-arid and sloppy terrains of the area (Kavalũla – meaning eroded land) in which I was brought up.

The water harvesting and soil conservation initiatives in this area is typically what propels my gardening motives. This hobby rewards directly as it is an economic pursuit in addition to contributing to the beauty of the surroundings. I look forward to participating in gardening events and workshops in the coming days and make a big story out of it.

On the other hand, my stories are based on past imaginations and views on various stages of life in relation to reality and current experiences. I appreciate to see some of my past dreams turning into a reality and find it worthwhile to share with other people with an objective of cultivating encouragement and exploring imaginations in unique perspectives of this world.

How did you hear about the 100 PhDs programme of the Excellence in Africa initiative?

An URL link bearing the EPFL-EXAF scholarship flyer was shared with me on WhatsApp by a former schoolmate.

What motivated you to submit an application?

The standard and prestige of the scholarship caught my attention.

How easy was it for you to go through the application process?

The application process was not difficult as I had made many other related applications before.

Can you present your project ? What is your research question(s)?

This research seeks to induce strong ferroic correlations in materials (multiferroics) that can lead to the creation of an innovative generation of devices characterized by high efficiency, low energy dissipation, and high storage density among other high-end capabilities.

Could you cite a few practical applications of your research?

Some of the envisioned applications include solid-state refrigeration, 4-state memory devices (for instance to produce more efficient cell phones, computers with less power consumption and more memory density), and solar cells with the capability to utilize the sun’s magnetic field in addition to the electric field.

What is the scientific challenge of your research topic?

Multiferroics are promising materials to improve the efficiency of many portable devices (e.g. mobile phones). However, so far, these materials only exhibit interesting properties (i.e., strong ferroic order coupling) at low temperatures, typically below 50 K (approximately -223 °C). Since most useful applications require room temperature operation, we must develop multiferroics with effective properties at room temperature to envisage a commercialization of the technology. There is no point (technologically and economically) to design portable devices (e.g., mobile phone batteries) that cannot function at room temperature or high-efficiency appliances (e.g., magnetoelectric solar cells) that cost more energy to create the system’s working conditions than it produces.

Could you briefly present your supervisor and your co-supervisor?

My supervisor is Daniel Wamwangi. He is an associate professor of physics at the University of the Witwatersrand, Johannesburg, South Africa. His research interests are in solid-state physics (condensed matter). On the other hand, Hugo Dil is my co-supervisor. He is a professor of physics at the Swiss Federal Institute of Technology (EPFL), Switzerland. His research interests are in spin properties of materials at reduced dimensionalities.

How do you benefit from the co-supervision of your supervisor in Africa and your co-supervisor at EPFL?

From the joint supervision, I am privileged to learn from experienced personnel with specialized knowledge and skills in different spheres.

How will the collaboration with EPFL help you to meet the scientific challenge described in the previous question ?

We have been able to grow strained films on the basis of atomic-layer-by-layer growth mode. Strain and reduced dimensionalities allow access to new physical properties not attainable in relaxed (bulk) materials. The successful growth of these tailored samples has been enabled by ultra-high-level control of sample growth conditions at the Paul Scherrer Institut - PSI (Swiss Light Source), courtesy of EPFL collaboration with PSI. Further data analyses will tell us more about the induced properties/new capabilities with respect to the ferroic correlations at various temperatures.

EPFL, in collaboration with PSI, enabled access to the state-of-the-art research infrastructures through which we could tailor the samples to improve their basic/functional properties towards practical applicability. Successful fabrication of the samples was occasioned by growth of strained thin films (monolayers and bilayers) in atomic layer-by-layer growth mode. This is only possible with high-level control of sample growth environment and experience.

Can you talk about your stay in Switzerland? How easy was it to prepare your venue to Switzerland?

The preparation for my venue in Switzerland was very smooth. This is because of the strong support I received, right from Prof. Hugo’s Office at EPFL to his collaborators at PSI (Prof. Milan Radovic’s team), and the church (Deacon Dr. Marcus Hüttner, Rebekka Stredwick, Pastors Hartmut Giessler and Ruedi Staehli).

What did you do?

I maintained constant touch with the Swiss team and never shied away to ask for guidance in any of the instances where I felt stuck.

Any funny or unexpected anecdotes you can share with us about your stay?

I was amused by three main qualities in Switzerland: amazing safety levels and hospitality of Swiss residents, and ‘dust-free’ natural environments!

What does excellence mean to you?

To me, excellence means beyond set standards, a quality that is generally attributed to exceptional abilities. In the context of the EPFL-EXAF 100 PhDs for Africa programme, I understand the excellence initiative as a deliberation to move research and teaching in Africa to levels way higher than the ‘African’ standards by empowering talented scholars from Africa with enabling atmosphere/capacity.