TOPTALENT2007
Application form
Complete this form either in English or in Dutch
Basic details1. Details of applicant
-Title(s), initial(s), first name: Marian
-Surname: Otter
-Male/female: female
-Private address for correspondence: Aquamarijnstraat 675, 9743 PS Groningen
-Preference for correspondence: in Dutch
-Telephone: 06 30181574
-E-mail:
-Website (optional):
2. Details of intended supervisor (‘promotor’)
Intended supervisor (‘promotor’):
-Title(s), initial(s), first name, surname: Prof. Dr. Ir.P.H.M. van Loosdrecht
-Work address for correspondence: Nijenborgh 4, 9747AG Groningen, The Netherlands
-Telephone:+31 (0)50 363 8149
-E-mail:
3. Host institution
RuG
4. Title of research idea
Magnetic heat transport in quasi-one-dimensional insulating oxides.
5.Summary of research idea
A highly efficient magnetic mode of thermal conduction, thermal conductivity ≈ 100 Wm-1K-1 around room temperature,occurs in novel quasi-one-dimensional insulating oxides. The basic properties and controllability of this thermal conduction path are investigated for potential use in electronic devices.
6. Research field
Sciences / technology(Chemistry, physics, mathematics, technical sciences, etc)
Research proposal
7. Brief description of research proposal (max. 2000 words!)
7.a Introduction
Thermal management is a major problem in electronic devices [1], such as further miniaturised microchips, hard disks, and interfaces between biological structures and semiconductor microstructures [2]. As, for example, more and more transistors are placed on a given area, the prevention of overheating in novel electronic devices becomes increasingly difficult. The relationship between the reliability and the operating temperature of a typical silicon semiconductor device shows that a reduction in the temperature leads to an exponential increase in the reliability and life expectancy of the device. Another example is given by magnetic sensors in recording heads which consist of multilayers of nanoscale thin films and are very susceptible to failures caused by thermally activated processes including interdiffusion, disruption of magnetic coupling among constituent layers or even melting. A further obstacle here is the decreasing sensitivity of spin valve sensors based on the giant magnetoresistance effect with rising temperature. Self-heating is therefore a key factor which limits the maximum permissible bias current and hence the amplitude of the sensor signal output. The use of high thermal conductivity materials is therefore essential for thermal management in compact packaging systems. Therequired thermal conductivity κ of effective materials is generally larger than 100 Wm-1K-1.
Low-dimensional quantum magnetic oxides might be able to provide an advanced and innovative way of thermal management. Until now phonons and/or electrons are mostly used for heat transport, while these new materials use magnetic excitations (magnons) as the heat carrying entity. The novel oxide materials efficiently and unidirectionally channel away parasitic heat such as that generated in integrated semiconductor circuits. An example of how a device will demonstrate the advantage of these materials in thermal management compared to conventional materials is illustrated in figure 1. A hot spot in a microelectronic structure is generating unwanted heat. This heat could hamper the performance of the heat releasing structure. Also, heat sensitive structures in its proximity could be damaged. A possible strategy for dissipating the heat is to use a layer with high thermal conduction to guide the heat to a sink. Left: A conventional heat conductor is normally roughly isotropic (3D heat conductor). The lateral temperature gradient is therefore small and sensitive structures have to be placed relatively far away. Right: In the case of a quasi one-dimensional heat conductor heat is channelled away and sensitive structures can be placed much closer.
Figure 1: Schematic illustration of a thermal management problem.
A next step will be to make the heat conduction controllable. This can be done in two ways. A first option is to change the magnon density by optically exciting magnetic excitations. A second option is to change the spin of the impurities in the sample (again using optical methods), which will influence the mean free path of the magnons.
Summarizing, the properties which are desirable for this innovative way of thermal management are
• a high thermal conductivity,
• a low or absent electrical conductivity,
• one-dimensional interactions, which brings directionality of heat flow,
• controllability of the heat conduction.
In 1997, it was established by the Foundation of Research and Technology - Hellas (FORTH) [3] that prototype models for one-dimensional magnetic compounds show unconventional – dissipationless – thermal transport. Experimentally, unusually large magnetic thermal conductivity has been observed in prototype materials (SrCuO2, Sr2CuO3, and (Sr, Ca, La)14Cu24O41) with quasi-one-dimensional spin arrangements in chain or ladder form [4-6]. An exceptionally high magnetic thermal conductivity κmag ≈ 100 Wm-1K-1 has been found at room temperature in high quality single crystals. [5] The magnetic heat conduction of these electrically insulating oxide materials is highly anisotropic, and dwarfs the lattice contribution by a factor of 50, as is shown in figure 2 on the next page.
Figure 2: Thermal conductivity of the spin ladder material La5Ca9Cu24O41, measured parallel (κ║) and perpendicular (κ┴) to the ladders. Data taken from [5].
Since its discovery this new mode of thermal transport has been extensively investigated both theoretically and experimentally. The crucial aspect of these materials is that at room temperature the magnetic heat conductivity κmag is as efficient as metallic heat conduction. However, compared to conventional materials with high thermal conductivity the multifunctionality of these novel compounds offers the following advantages:
• These compounds are electrically insulating and can therefore be used to simultaneaously electrically insulate electronic circuits and carry away heat.
• Heat is conducted primarily along one crystal axis, hence the material can thermally insulate in two directions and carry away heat along the third.
• Heat is carried by localized spins which can be manipulated with magnetic fields or light. Therefore, an electrical insulator with tunable heat conductivity at room temperature could emerge.
7.b Research questions
The main goal of this project is to understand how heat is transported by magnetic modes (magnons) in quasi-one-dimensional insulating oxides. The questions we want to answer are
• How does the heat conductivity depend on material quality, density of magnons and mean free path? We will measure the thermal conductivity of different samples as a function of temperature, to change the magnon density and the mean free path of the magnons. This will be done in cooperativity with the IFW Dresden. (group of C. Hess)
• What is the effect of magnetic and non-magnetic impurities, which change the mean free path of the magnons, on the heat conductivity?
• What is the effect of an extremely high density of magnons? It is reported [7] that Bose-Einstein condensation of magnons at room temperature can be realized at high densities, which will lead to an enhanced thermal conductivity.
• How can we control the density and spin states of impurities to achieve a controllable switching or tuning of the heat conductivity of these new materials?
7.c Method/Approach
Crystals will be grown by the Université Paris Sud, mainly using the Travelling Solvent Floating Zone Method (TSFZ-Method). Also, in Groningen we will fabricate epitaxial thin films of magnetic compounds with high thermal conductivity using pulsed laser deposition technique (PLD). In parallel, also PLD thin film growth will be persued at the University of Cyprus for us.
First the thermal properties of the material will be characterized by measuring the spatially and time resolved Raman Stokes/Anti-Stokes phonon and magnetic modes to determine the local lattice temperature. Also optical spectroscopy in the mid infrared will be done to study the magnetic excitations. The temperature profile established along the sample surface when one side of the sample is heated will be measured. These methods will provide the optical excitation energies of the magnetic excitations which will be used to switch κmag via the optical generation of these magnetic excitations. An optical pump/probe technique will be used to optically generate magnetic excitations and probe their propagation as a function of time and space. The microscope has a resolution of 1 μm. In a last step, this technique will be combined with the application of temperature gradients, strain and heat pulses, aiming towards an optical switching of κmag.
To create a high density of magnons at room temperature, a microstrip resonator will be used attached to the thin film, which creates a microwave pumping field. Detection of the signal is done using time resolved Brillouin light scattering (BLS) spectroscopy.
7.d Innovation
Until now, the envisaged quasi-one-dimensional quantum magnetic ceramic oxides have been neither incorporated into thin film structures nor utilized in thermal management applications. The exploitation of one-dimensional heat transport offers an especially high innovative potential: thermal management applications can be envisaged in several future technological components such as highly integrated CMOS (complementary metal oxide semiconductor) technology, computer hard drives, magnetic sensors or bio-compatible microchips. Furthermore, new microscopic methods of temperature regulations could emerge via a local change of thermal conductivity. Finally, fundamental knowledge related to the novel one-dimensional transport phenomena which have been observed in quantum magnetic systems will be acquired. These phenomena include extraordinary magnetic heat transport, and dissipationless spin transport, which could reveal hitherto unexplored ways of transporting spin information and thereby enrich the emerging field of spintronics.
7.e Relevance for science, technology or society
The project focuses on new material-based solutions for thermal management in micro and nanoelectronics within semiconductor industry. By exploring the magnetic thermal conductivity κmag it is tried to explore a new approach to cope with the thermal management problems arising in present, future and emergent micro and nanoelectronic technologies. This concerns in particular the establishment of a switching mechanism for κmag. The approach involves research on new ideas which aims at developments clearly beyond the current state of the art. Furthermore, the quasi-one-dimensional systems considered also show unconventional – dissipationless – electrical and spin transport besides the extraordinary thermal conductivity that is the main focus of this project. Thus, in long term, they will also be of interest in nanoelectronics and the emerging priority field of spintronics.
7.f Commercial applications
In this project, there is a collaboration with a compagny, ZMD (department Analog Mixed Signal Services GmbH & Co. KG). This provides a path to bring new technology to customers. The compagny will, among other things, investigate the feasibility for automotive applications. The compagny has around 750 worldwide and an 80.4 million Euro revenue in 2003. It’s innovative products are used in automotive and industrial electronics, medical devices and infrared data transmission applications such as mobile phones and remote controls. More information can be found on
7.gLiterature references
[1] High thermal conductivity materials, K. Watari, S.L. Shinde, MRS Bulletin 26, 440 (2001)
[2] Semiconductor chips with ion channel, nerve cells and brain, P. Fromherz, Physica E 16, 24 (2003)
[3] Transport and conservation laws, X. Zotos, F. Naef, P. Prolovsek, Phys. Rev. B 55, 11029 (1997)
[4] Thermal conductivity of the hole-dropped spin ladder systems Sr14-xCaxCu24O41, A.V. Sologubenko, K. Giannó, H.R. Ott, U. Ammerahl, A. Revcolevschi, Phys. Rev. Lett. 84, 2714 (2000)
[5] Magnon heat transport in (Sr, Ca, La)14Cu24O41, C. Hess, C. Baumann, U. Ammerahl, B. Büchner, F. Heidrich-Meisner, W. Brenig, A. Revcolevschi, Phys. Rev. B 64, 184305 (2001)
[6] Heat transport by lattice and spin excitations in the spin-chain compounds SrCuO2 and Sr2CuO3, A.V. Sologubenko, K. Giannó, H.R. Ott, A. Vietkine, A. Revcolevschi, Phys. Rev. B 64, 054412 (2001)
[7] Bose-Einstein condensation of quasi-equilibrium magnons at room temperature under pumping, S.O. Demokritov, V.E. Demidov, O. Dzyapko, G.A. Melkov, A.A. Serga, B. Hillebrands, A.N. Slavin, Nature 443, 05117 (2006)
Indicate the total number of words: 1705
7h.Plan of work (2007-2011)
2007 / Growing thin films using PLD technique.
2008 / Measuring the thermal conductivity as a function of material quality and temperature (in cooperation with IFW Dresden), making a theoretical model of the system in cooperation with C. de Morais-Smith of the University of Utrecht,Raman spectroscopy.
2009 / Investigating the effect of impurity density on the thermal conductivity, investigating the effect of the type of impurities on the thermal conductivity.
2010 / Investigating the effect of a very high density of magnons on the thermal conductivity, feasibility study of switching or tuning of the thermal conductivity of the materials.
2011 / Writing Phd-thesis.
Cost estimates
8.1. Personnel positions
One PhD student for a period of four years. This will cost around 172.000 euros.
8.2. Running budget
There will be trips to Dresden for meetings. Also, some of the experiments will be done there. We estimate the costs to be around 3000 euros.
8.3. Equipment
Inhouse equipment: Pulsed laser deposition (PLD), Raman stokes/anti-stokes setup, mid-infrared setup (except for the cryostat), Brillouin light scattering setup.
What should be bought is: a cryostat for the mid-infrared setup (costs around 30.000 euros) and a microstrip resonator (costs around 500 euros).
8.4. Budget summary
costs are given in kilo euros.
2007 / 2008 / 2009 / 2010 / 2011 / TOTALPersonnel(positions):
PhD students
Postdocs
Technicians
Guests / 1 / 1 / 1 / 1 / 1 / 1
Personnel (costs)
Running budget
Equipment FOM-part / 13
4.8
30 / 38
17
0 / 43
15.5
0 / 46
15.5
0.5 / 32
10.2
0 / 172
63
30.5
TOTAL (requested from FOM / 47.8 / 55 / 58.5 / 62 / 42.2 / 265.5
8.5 Have any other grants for this project or for the applicantbeen requested either from NWO or from any other institution?
no
Curriculum vitae
9. Personal details
Applicant
-Title(s), initial(s), first name: Marian
-Surname: Otter
-Nationality:Dutch
-Date of birth:6 October 1983
-Country and place of birth: Emmen, The Netherlands
Parents
-Country of birth father:The Netherlands
-Country of birth mother: The Netherlands
10. Secondary education
School type: VWO (Gymnasium) at the EsdalCollege, two profiles (Natuur&Techniek, Natuur&Gezondheid), Greek and Latin languages.
City and country: Emmen, The Netherlands
Period: September 1996 – June 2002
Graduation date:18 June 2002, cum laude
11. Bachelor's degree
University/College of Higher Education: RuG
Faculty/discipline:Applied Physics, with 206 EC’s instead of 180. Part of these courses (18 EC’s) are not related to physics, these are ‘Latijn vertaalpracticum 1’, ‘Nieuwe religieuze bewegingen en New Age’ and ‘Emotionele intelligentie en communicatie’. It was obligatory to follow a 5 EC course outside our faculty. Because of my broad interest, I decided to do some more.
City and country:Groningen, The Netherlands
Period: September 2002 - August 2005
Date Bachelor’s degree:31 August 2005
Grade average:7.45
12. Research master's
University: RuG
Faculty/discipline: topmaster nanoscience, with 126 EC’s instead of 120. I decided to do some extra courses to have a better background knowledge for my master research. All of these courses are related to my discipline.
The topmaster nanoscience is organized by the national research center ‘Materials Science Center’.The topmaster aims at an interdisciplinarytraining in modern materials science, with a focus on nanoscale phenomena. It combines elements of physics, chemistry and biology. Teachers and supervisors associated with the programme represent the excellent research groups taking part in the MSC research programme.Students are submitted to a challenging and highly demanding curriculum, combining both the broadness and depth necessary for a successful research career in modern materials science.
To enroll the topmaster, one must pass a strict selection procedure (around 20 percent of the applicants passes). Information about the topmaster nanoscience, like the curriculum and the admission procedure, can be found on
City and country:Groningen, The Netherlands
Period: September 2005 - August 2007
ExpecteddateMaster’s degree:August 2007, expected cum laude
Grade average(so far): 8.0
Title Master’s thesis (if applicable): Excitons in Cuprous Oxide (preliminary)
Grade for thesis (if applicable):
13. Motivation for application (max. 80 words!)
I’d like to explore things that are unknown at the moment. Momentarily I am involved in the topmaster nanoscience, which prepares me for doing research. I already decided that I want to do a PhD, because I am interested in an academic career. The big advantage for me in doing my PhD via the toptalent programme, is that I can define my own research project, which allows me to expand my knowledge in the direction I want.
14. Current work experience (if applicable)
None
15. Previous relevant work experience (if applicable)
Part-time job in a supermarket (Schippers, Odoorn, The Netherlands). Tasks and responsibilites
included: providing customer service at the Post Office counter, working as a cashier, stacking
shelves, and cleaning duties.(1998 – 2005) I learned to work in a team, to work self-employed, to
take responsibility, and to handle problems.
16. International activities (if applicable)
- Visit DESY (Deutsches Elektronen-SYnchrotron), Hamburg (2005). Information about DESY can be found on
- Visit Japan, University of Tokyo (1 April – 15 June 2007). I will do a part of my topmaster research here in the research group of professor Gonokami.Information about this research group can be found on
17. Other academic activities (if applicable)
- Chair of the organization of the 3rd nanoscience symposium of the Materials Science Center (June 2006). The program can be found on
- Student member of the board of the educational institute nanoscience. (2005 – 2007)
- Member of the Curriculum Committee of the topmaster nanoscience. (2005 – 2007)
- Member of the sports committee of the FMF (student association for physics, mathematics, and computer sciencestudents, around 600 members, see sportcie.fmf.nl). (2005 – 2007) From September 2006 until June 2007, I am the chair of this committee. We organize different sports events for students, e.g. indoor football, swimming, running, cycling and paintball.
- Member tenure track search committee for a professor in polymer chemistry. (tt “benoemingsadviescommissie”) (2006 – 2007)
- Organisation ‘Eén dag student 2006’. We show high school students what they can expect when they will decide to do their study in (applied) physics in Groningen. (21 November 2006) I think it is very important to make physics attractive for high school students and to promote it to a broad public.
18. Research grants and prizes (if applicable)
- Scholarship for the topmaster nanoscience, paid by the Materials Science Center (September 2005 - August 2007).