A PhD fellowship on studying permanent magnets using a micromagnetism modeling framework is now available at the Department of Energy Conversion and Storage, Technical University of Denmark in collaboration with the Poul Due Jensen Foundation.
This PhD position at DTU Energy will constitute one part in a unique research project where we want to model permanent magnets on the microstructural level to understand why their resistance to opposing magnetic fields, their so-called coercivity, is much lower than theoretically predicted. The coercivity is the magnetic field that the permanent magnet can withstand before it flips and points in the opposite direction. We will study this phenomenon by realizing a novel and fast computational model built on an existing computational framework for magnetic field calculation written in Fortran.
For all known permanent magnet materials, the observed coercivity is at most 40% of the theoretical value. This discrepancy between the theoretical calculation of the coercive magnetic field and the observed coercive field of permanent magnets is known as Brown’s paradox. In this project, we will study this paradox for the most powerful permanent magnets available: NdFeB magnets. The goal of this project is to determine what physical mechanism causes Browns paradox. This will be done by realizing a new and much more powerful micromagnetism model by expanding our current mesoscale model for magnetism to include the physics needed for a micromagnetism model. Micromagnetic systems are governed by several interplaying physical mechanisms, namely exchange interaction, crystal anisotropy, Zeeman effect and macroscopic demagnetization. Once Browns paradox has been understood, the following logical step will be to propose a mechanism that alleviates the coercivity problem.
Your role as a PhD student will be to expand our magnetism model to a full dynamic micromagnetism model together with a post doc in the project. Once this is done, you will use the model to explore Brown’s paradox and the mechanisms reducing coercivity in permanent NdFeB magnets. We have a US partner in the project and as a PhD student you would spend about three to six months there to learn about micromagnetism and coercivity reducing phenomena.
At the end of the PhD project, we will have developed fully open source model framework for micromagnetic simulations and have investigated the coercivity reducing phenomena and thereby explained Brown’s paradox. The main activity will take place at the Department of Energy Conversion and Storage at DTU Risø campus initially and from ultimo 2019 at DTU Lyngby campus, as the department is being united at this campus.
Candidates should have a two-year master's degree (120 ECTS points) or a similar degree with an academic level equivalent to a two-year master's degree, preferably in physics, engineering or a science-related discipline.
- Good understanding of numerical modelling
- Good communication skills in English
- Being able to work independently and in a team
Candidates with the following qualifications are preferred
- Experience with magnetism or electromagnetism
- Experience with high performance computing
- Experience with Fortran, Matlab or similar software
- Experience with numerical modelling of temporal systems
Approval and Enrolment
The scholarship for the PhD degree is subject to academic approval, and the candidate will be enrolled in one of the general degree programmes at DTU. For information about our enrolment requirements and the general planning of the PhD study programme, please see the DTU PhD Guide.
DTU is a leading technical university globally recognized for the excellence of its research, education, innovation and scientific advice. We offer a rewarding and challenging job in an international environment. We strive for academic excellence in an environment characterized by collegial respect and academic freedom tempered by responsibility.
Salary and appointment terms
The appointment will be based on the collective agreement with the Danish Confederation of Professional Associations. The allowance will be agreed upon with the relevant union.
The period of employment is 3 years.
You can read more about career paths at DTU here.
The expected starting date is March 2019 or thereafter.
Please contact Associate Professor Rasmus Bjørk, firstname.lastname@example.org and Associate Professor Kaspar K. Nielsen, email@example.com, for further information.
Please do not send applications to this e-mail address, instead apply online as described below.
Please submit your online application no later than 1 February 2019 (local time).
Apply at www.career.dtu.dk
To apply, please open the link "Apply online", fill out the online application form. The following must be attached in English:
- A letter motivating the application (cover letter)
- Curriculum vitae
- Grade transcripts and BSc/MSc diploma
- Excel sheet with translation of grades to the Danish grading system (see guidelines and Excel spreadsheet here)
All interested candidates irrespective of age, gender, race, disability, religion or ethnic background are encouraged to apply.
DTU Energy is focusing on functional materials and their application in sustainable energy technology. Our research areas include fuel cells, electrolysis, solar cells, magnetic refrigeration, superconductivity and thermoelectrics. Additional information about the department can be found on www.ecs.dtu.dk
DTU is a technical university providing internationally leading research, education, innovation and scientific advice. Our staff of 6,000 advance science and technology to create innovative solutions that meet the demands of society, and our 11,200 students are being educated to address the technological challenges of the future. DTU is an independent academic university collaborating globally with business, industry, government and public agencies.