Asmaa Qdemat

Asmaa Qdemat

PGSB Fellow
Al-Quds Univeristy & RWTH Aachen University

Department: Physics

Faculty: science and technology

Specialization: Physics

Accurate Specialization: solid state physics

Palestinian supervisor: Dr. Salman Salman

Palestinian Supervisor affiliation: Physics Department/Faculty of Science/ Al Quds University

Degree aims: PhD

FZJ Supervisor: Prof. Dr. Thomas Brückel

Center in Juelich: Full Name with abbreviaion: Jülich Centre for Neutron Science JCNS and Peter Grünberg Institut PGI Quantum Materials and Collective Phenomena JCNS-2 / PGI-4 (JCNS-2)

Affiliated University in Germany: RWTH Aachen University

Department: Physics

Faculty: science

The mission research period: 02/2016 – 10/2019

Title of Research: Structural and Magnetic Characterization in 2D and 3D ordered nanoparticle assemblies

Research Purpose; The main aim of my research is an investigation of the structural and magnetic correlations of highly ordered assemblies of magnetic nanoparticles deposited on a surface. Regular arrangements of magnetic nanoparticles into 2D and 3D highly ordered structures are fundamentally interesting regarding the understanding of magnetic interactions, for a rational design towards potential applications in information technology and spintronics and due to their unique optical and electronic properties which strongly differ from those of the individual building blocks due to the structural and magnetic ordering inside self-assembled systems. In order to reach high coherence of the lateral order, the nanoparticles deposited on pre-patterned substrates, obtained using several top-down and bottom-up processes. The structural order investigated by small angle x-ray scattering under grazing incidence and the magnetic order will be investigated in the near future by small angle neutron scattering under grazing incidence with polarization analysis.

Main outputs/results:

  1. A facial approach for fabricating a monolayer film of SiO2 NPs was developed successfully. Using the stearyl alcohol as an assistant by adding it to the colloidal NP dispersion from which the monolayers are formed, a large-scale monolayer film of well-ordered, uniform-sized SiO2 NPs was fabricated on a silicon substrate. The film exhibited a two-dimensional(2D) hexagonal close-packed (HCP) structure. Structural characterization of the obtained Si2 NPs monolayer was done locally by Scanning Electron Microscopy (SEM), and globally by X-ray reflectivity (XRR) and grazing incidence small-angle X-ray scattering (GISAXS), where the data was reproduced by simulation within the Distorted Wave Born Approximation (DWBA) [1].
  2. The effects of dipolar interparticle interaction on the magnetic properties of self-assembled structures of magnetic nanoparticles are studied. The collective magnetism is studied for an ordered 2D hexagonal arrays of ferrimagnetic cobalt ferrite (CFO) nanodots on Si substrates. The dot size and their long-range arrangement were studied by SEM, XRR and GISAXS with simulation using the BornAgain software. We deduce both the height profile of the individual nanoparticles and a hexagonal ordering between the nanoparticles. The magnetism of the arranged nanodots is resolved using a superconducting quantum interference device (SQUID) and the magnetic depth profile of NP monolayer at various applied magnetic fields was deduced from polarized neutron reflectivity (PNR) measurements [2].
  3. A highly ordered 3D arrangements of cubic and spherical magnetic NPs obtained using assisted self-assembly method where a pre-patterned substrate used which is obtained using several top-down and bottom-up processes with a feature-size of the same order of magnitude as the diameter of the nanoparticles. Then the structure of the obtained system is resolved by XRR and GISAXS. The magnetic anisotropy and the collective magnetic behavior are investigated using SQUID magnetometry [3].

Main Impact: Highly ordered assemblies of magnetic nanoparticles have an impact on the creation of next-generation material design and for future electronic and magnetic nano-devices that require highly ordered arrangements of NPs over large areas formed with a simple method at low cost to meet the growing industrial needs.

Sharing lectures:

  1. JCNS laboratory course neutron scattering, Jülich center for neutron, Jülich, Germany at Forschungszentrum Jülich and Heinz Maier-Leibnitz zentrum, Garching, Munich. 2016 and 2017.

        2. Spring School, Jülich Germany (2013, 2015, 2016, 2017, 2019)

      3. Condensed-matter physics (I & II) at RWTH Aachen university.

Sharing Conferences: 

[1] Qdemat, Asma & Kentzinger, Emmanuel & Buitenhuis, Johan & Rücker, Ulrich & Ganeva, Marina & Brückel, Thomas. (2020). “Self assembled monolayer of silica nanoparticles with improved order by drop casting”. RSC Advances. 10. 18339-18347. 10.1039/D0RA00936A.
[2] A. Qdemat, E. Kentzinger, J. Xu, G. Portale, M. Ganeva, S. Mattauch, T. Brückel. ” 2D Ordered Arrays of Ferrimagnetic Cobalt Ferrite Nanodots: X-ray and Polarized Neutron Reflectivity”, in preparation.
[3] Wang, Liming & Qdemat, Asma & Petracic, Oleg & Kentzinger, Emmanuel & Rücker, Ulrich & Zheng, Fengshan & Lu, Penghan & Wei, Xiankui & Dunin-Borkowski, Rafal & Brückel, Thomas. (2019). “Manipulation of dipolar magnetism in low-dimensional iron oxide nanoparticle assemblies”. Physical Chemistry Chemical Physics. 21. 10.1039/C9CP00302A.
[4] Hanbali, Ghadeer & Jodeh, Shehdeh & Hamed, Othman & Bol, Roland & Khalaf, Bayan & Qdemat, Asma & Samhan, S.. (2020). “Enhanced Ibuprofen Adsorption and Desorption on Synthesized Functionalized Magnetic Multiwall Carbon Nanotubes from Aqueous Solution”. Materials. 13. 3329. 10.3390/ma13153329.