
Dr hab. Aleksandra Trzaskowska, prof. UAM
- Tel: +48 61 829 5197
- Loc: wing G, first floor, room 180
- Email: olatrzas@amu.edu.pl
Scientific degrees
M.Sc. in experimental physics,
Faculty of Physics, Adam Mickiewicz University, Poznań, 2000;
„Elastic properties of Gd2(MoO4)3 crystal investigated by using Brillouin spectroscopy”
Ph.D. in experimental physics,
Faculty of Physics, Adam Mickiewicz University, Poznań, 2005;
„Surface phonons in ferroelastic crystals”
supervisor: prof. dr hab. Sławomir Mielcarek
Habilitation in experimental physics,
Faculty of Physics, Adam Mickiewicz University, Poznań, 2018;
“Dispersion of surface waves in phononic crystals investigated by high- resolution Brillouin spectroscopy”
Research interests
keywords: phonons, phononic crystals, Brillouin spectroscopy, Finite Element Method
My research interests are mainly focused on studying the elastic and magnetic properties of materials of various types. I investigate experimentally (Brillouin spectroscopy) and theoretically (Finite Element Method) propagation of bulk and surface elastic waves in crystals and layered materials. By using Dynamic Mechanical Analysis, I study elastic properties of bones. I also investigate spin waves propagation in magnetic materials by Brillouin spectroscopy.
Publications
2023 |
|
7. | Sreedevi Janardhanan, Sławomir Mielcarek, Piotr Kuświk, Maciej Krawczyk, Aleksandra Trzaskowska High-resolution Brillouin light scattering study on Ti/Au/Co/Ni multilayer Journal of Magnetism and Magnetic Materials, 586 , pp. 171209, 2023, ISSN: 0304-8853. @article{JANARDHANAN2023171209, title = {High-resolution Brillouin light scattering study on Ti/Au/Co/Ni multilayer}, author = {Sreedevi Janardhanan and Sławomir Mielcarek and Piotr Kuświk and Maciej Krawczyk and Aleksandra Trzaskowska}, url = {https://www.sciencedirect.com/science/article/pii/S0304885323008594}, doi = {https://doi.org/10.1016/j.jmmm.2023.171209}, issn = {0304-8853}, year = {2023}, date = {2023-09-01}, journal = {Journal of Magnetism and Magnetic Materials}, volume = {586}, pages = {171209}, abstract = {The topic of this paper addresses the Brillouin light scattering (BLS) study of the spin-wave and surface acoustic wave dynamics in the multilayer consisting of Ti/Au/Co/Ni deposited on Si substrate. We make the quantitative analysis of spin-wave frequency under a range of wave vectors to determine the dispersion relation and to study the effect of the magnetic field. These findings were correlated with theoretical models to determine the magnetic system parameters, such as magnetization, Lande g factor, exchange stiffness constant etc. In addition to this, we have conducted finite element method based simulations to understand the nature of surface phonons and to determine the elastic tensor parameters for the Ti/Au/Co/Ni layer from the fitting of simulation results with the experiment data points.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The topic of this paper addresses the Brillouin light scattering (BLS) study of the spin-wave and surface acoustic wave dynamics in the multilayer consisting of Ti/Au/Co/Ni deposited on Si substrate. We make the quantitative analysis of spin-wave frequency under a range of wave vectors to determine the dispersion relation and to study the effect of the magnetic field. These findings were correlated with theoretical models to determine the magnetic system parameters, such as magnetization, Lande g factor, exchange stiffness constant etc. In addition to this, we have conducted finite element method based simulations to understand the nature of surface phonons and to determine the elastic tensor parameters for the Ti/Au/Co/Ni layer from the fitting of simulation results with the experiment data points. |
6. | Shashank Shekhar, Sławomir Mielcarek, Y Otani, Bivas Rana, Aleksandra Trzaskowska Influence of CoFeB layer thickness on elastic parameters in CoFeB/MgO heterostructures Scientific Reports, 13 (1), pp. 10668, 2023, ISSN: 2045-2322. @article{shekhar_influence_2023, title = {Influence of CoFeB layer thickness on elastic parameters in CoFeB/MgO heterostructures}, author = {Shashank Shekhar and Sławomir Mielcarek and Y Otani and Bivas Rana and Aleksandra Trzaskowska}, url = {https://www.nature.com/articles/s41598-023-37808-4}, doi = {10.1038/s41598-023-37808-4}, issn = {2045-2322}, year = {2023}, date = {2023-01-01}, urldate = {2023-07-04}, journal = {Scientific Reports}, volume = {13}, number = {1}, pages = {10668}, abstract = {The surface acoustic waves, i.e., surface phonons may have huge potential for future spintronic devices, if coupled to other waves (e.g., spin waves) or quasiparticles. In order to understand the coupling of acoustic phonons with the spin degree of freedom, especially in magnetic thin film-based heterostructures, one needs to investigate the properties of phonons in those heterostructures. This also allows us to determine the elastic properties of individual magnetic layers and the effective elastic parameters of the whole stacks. Here, we study frequency versus wavevector dispersion of thermally excited SAWs in CoFeB/MgO heterostructures with varying CoFeB thickness by employing Brillouin light spectroscopy. The experimental results are corroborated by finite element method-based simulations. From the best agreement of simulation results with the experiments, we find out the elastic tensor parameters for CoFeB layer. Additionally, we estimate the effective elastic parameters (elastic tensors, Young’s modulus, Poisson’s ratio) of the whole stacks for varying CoFeB thickness. Interestingly, the simulation results, either considering elastic parameters of individual layers or considering effective elastic parameters of whole stacks, show good agreement with the experimental results. These extracted elastic parameters will be very useful to understand the interaction of phonons with other quasiparticles.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The surface acoustic waves, i.e., surface phonons may have huge potential for future spintronic devices, if coupled to other waves (e.g., spin waves) or quasiparticles. In order to understand the coupling of acoustic phonons with the spin degree of freedom, especially in magnetic thin film-based heterostructures, one needs to investigate the properties of phonons in those heterostructures. This also allows us to determine the elastic properties of individual magnetic layers and the effective elastic parameters of the whole stacks. Here, we study frequency versus wavevector dispersion of thermally excited SAWs in CoFeB/MgO heterostructures with varying CoFeB thickness by employing Brillouin light spectroscopy. The experimental results are corroborated by finite element method-based simulations. From the best agreement of simulation results with the experiments, we find out the elastic tensor parameters for CoFeB layer. Additionally, we estimate the effective elastic parameters (elastic tensors, Young’s modulus, Poisson’s ratio) of the whole stacks for varying CoFeB thickness. Interestingly, the simulation results, either considering elastic parameters of individual layers or considering effective elastic parameters of whole stacks, show good agreement with the experimental results. These extracted elastic parameters will be very useful to understand the interaction of phonons with other quasiparticles. |
2022 |
|
5. | Aleksandra Trzaskowska, Sławomir Mielcarek, Tomasz Lehmann, Ewa Pruszyńska-Oszmałek, Paweł Kołodziejski, Maciej Głowacki Mechanical properties of the mouse femur after treatment with diclofenac and running exercises Acta of Bioengineering and Biomechanics, 24 (2), pp. null, 2022. @article{TrzaskowskaMechanical2022, title = {Mechanical properties of the mouse femur after treatment with diclofenac and running exercises}, author = {Aleksandra Trzaskowska and Sławomir Mielcarek and Tomasz Lehmann and Ewa Pruszyńska-Oszmałek and Paweł Kołodziejski and Maciej Głowacki}, url = {https://www.actabio.pwr.wroc.pl/Vol24No2/33.pdf}, doi = {10.37190/abb-02061-2022-03}, year = {2022}, date = {2022-05-26}, journal = {Acta of Bioengineering and Biomechanics}, volume = {24}, number = {2}, pages = {null}, abstract = {The flexible properties of the bone are essential for the movement and protection of vital organs. The ability of a bone to resist fractures under the influence of large muscles and physical activity depends on its established mechanical properties. This article discusses how exercise such as treadmill running and taking non-steroidal anti-inflammatory drugs (NSAIDs), such as diclofenac, affect the musculoskeletal system by modifying the elastic and thermal properties of the left femur of a mouse. Methods: The research was conducted using 9-week-old C57BL/6J female mice. In order to investigate the elastic and thermal properties of bones, dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC) were performed. Results: The study of elastic properties, followed by in-depth statistical analysis, shows that taking diclofenac slightly reduces the elastic parameters of the bones under study. These changes are more pronounced in DSC studies, the shift of the observed endothermic peaks is on the order of several degrees with a simultaneous increase in the enthalpy of this process. Conclusions: The opposite effect of the applied factors – diclofenac and running – on the elastic properties of the bones of the examined mice was found. The external factors – running and diclofenac – modify the basic parameters of the endothermic process associated with the release of water.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The flexible properties of the bone are essential for the movement and protection of vital organs. The ability of a bone to resist fractures under the influence of large muscles and physical activity depends on its established mechanical properties. This article discusses how exercise such as treadmill running and taking non-steroidal anti-inflammatory drugs (NSAIDs), such as diclofenac, affect the musculoskeletal system by modifying the elastic and thermal properties of the left femur of a mouse. Methods: The research was conducted using 9-week-old C57BL/6J female mice. In order to investigate the elastic and thermal properties of bones, dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC) were performed. Results: The study of elastic properties, followed by in-depth statistical analysis, shows that taking diclofenac slightly reduces the elastic parameters of the bones under study. These changes are more pronounced in DSC studies, the shift of the observed endothermic peaks is on the order of several degrees with a simultaneous increase in the enthalpy of this process. Conclusions: The opposite effect of the applied factors – diclofenac and running – on the elastic properties of the bones of the examined mice was found. The external factors – running and diclofenac – modify the basic parameters of the endothermic process associated with the release of water. |
4. | Aleksandra Trzaskowska, P Graczyk, Nandan K. P. Babu, Miłosz Zdunek, H Głowiński, Jarosław W. Kłos, Sławomir Mielcarek The studies on phonons and magnons in [CoFeB/Au]N multilayers of different number of repetitions Journal of Magnetism and Magnetic Materials, 549 , pp. 169049, 2022, ISSN: 0304-8853. @article{TRZASKOWSKA2022169049, title = {The studies on phonons and magnons in [CoFeB/Au]N multilayers of different number of repetitions}, author = {Aleksandra Trzaskowska and P Graczyk and Nandan K. P. Babu and Miłosz Zdunek and H Głowiński and Jarosław W. Kłos and Sławomir Mielcarek}, url = {https://www.sciencedirect.com/science/article/pii/S0304885322000300}, doi = {https://doi.org/10.1016/j.jmmm.2022.169049}, issn = {0304-8853}, year = {2022}, date = {2022-01-13}, journal = {Journal of Magnetism and Magnetic Materials}, volume = {549}, pages = {169049}, abstract = {We investigated the interaction between spin waves and surface acoustic waves in the [CoFeB/Au]N multilayer deposited on the silicon substrate by Brillion light scattering spectroscopy. We showed that this kind of coupling manifested as an anticrossing in magnetoelastic dispersion relation, can be modified by changing the number of repetitions within the multilayer. The observed modification is attributed mostly to the change in the strength of dipolar interactions which alter the dispersion branch of spin wave fundamental mode and shifts the anticrossing towards larger wave vectors where the magnetoelastic coupling is stronger. The studied range of the wave vector was varied between 0.6·105 cm−1 and 2.2·105 cm−1 while the frequency range of investigations was between 3 and 20 GHz.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We investigated the interaction between spin waves and surface acoustic waves in the [CoFeB/Au]N multilayer deposited on the silicon substrate by Brillion light scattering spectroscopy. We showed that this kind of coupling manifested as an anticrossing in magnetoelastic dispersion relation, can be modified by changing the number of repetitions within the multilayer. The observed modification is attributed mostly to the change in the strength of dipolar interactions which alter the dispersion branch of spin wave fundamental mode and shifts the anticrossing towards larger wave vectors where the magnetoelastic coupling is stronger. The studied range of the wave vector was varied between 0.6·105 cm−1 and 2.2·105 cm−1 while the frequency range of investigations was between 3 and 20 GHz. |
2021 |
|
3. | Aleksandra Trzaskowska, Sławomir Mielcarek, M Wiesner, F Lombardi, Bogusław Mróz Ultrasonics, 117 , pp. 106526, 2021. @article{TRZASKOWSKA2021106526, title = {Dispersion of the surface phonons in semiconductor/topological insulator Si/Bi2Te3 heterostructure studied by high resolution Brillouin spectroscopy}, author = {Aleksandra Trzaskowska and Sławomir Mielcarek and M Wiesner and F Lombardi and Bogusław Mróz}, url = {https://www.sciencedirect.com/science/article/pii/S0041624X21001554}, doi = {https://doi.org/10.1016/j.ultras.2021.106526}, year = {2021}, date = {2021-07-21}, journal = {Ultrasonics}, volume = {117}, pages = {106526}, abstract = {The dynamics and dispersion of surface phonons in heterostructure semiconductor/ topological insulator Si/Bi2Te3 was investigated using high resolution Brillouin light scattering method in the GHz frequency range. Both Rayleigh and Sezawa surface acoustic waves have been observed for wave vectors ranging from 0.006 to 0.023 nm−1. Anomaly in dispersion relations ω(q) for both surface waves were detected for the wave vector q = 0.016 nm−1. The finite element method (FEM) was used to simulate the observed shapes of ω(q) and to find the deformation profiles of surface acoustic waves. We attribute the observed changes to the coupling between low energy electrons and surface phonons. The coupling between helical Dirac states and surface phonons is discussed in the frame of accessible theoretical models.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The dynamics and dispersion of surface phonons in heterostructure semiconductor/ topological insulator Si/Bi2Te3 was investigated using high resolution Brillouin light scattering method in the GHz frequency range. Both Rayleigh and Sezawa surface acoustic waves have been observed for wave vectors ranging from 0.006 to 0.023 nm−1. Anomaly in dispersion relations ω(q) for both surface waves were detected for the wave vector q = 0.016 nm−1. The finite element method (FEM) was used to simulate the observed shapes of ω(q) and to find the deformation profiles of surface acoustic waves. We attribute the observed changes to the coupling between low energy electrons and surface phonons. The coupling between helical Dirac states and surface phonons is discussed in the frame of accessible theoretical models. |
2. | Tomasz Lehmann, Magdalena Wojtków, Ewa Pruszynska-Oszmałek, Paweł Kołodziejski, Celina Pezowicz, Aleksandra Trzaskowska, Sławomir Mielcarek, Mirosław Szybowicz, Ariadna B Nowicka, Marek Nowicki, Ewa Misterska, Ewa Iwańczyk-Skalska, Paweł Jagodziński, Maciej Głowacki Acta of Bioengineering and Biomechanics, 23 (3), pp. 1 -17, 2021. @article{000231402, title = {Trabecular bone remodelling in the femur of C57BL/6J mice treated with diclofenac in combination with treadmill exercise}, author = {Tomasz Lehmann and Magdalena Wojtków and Ewa Pruszynska-Oszmałek and Paweł Kołodziejski and Celina Pezowicz and Aleksandra Trzaskowska and Sławomir Mielcarek and Mirosław Szybowicz and Ariadna B Nowicka and Marek Nowicki and Ewa Misterska and Ewa Iwańczyk-Skalska and Paweł Jagodziński and Maciej Głowacki}, url = {http://www.actabio.pwr.wroc.pl/Vol23No3/41.pdf}, year = {2021}, date = {2021-05-13}, journal = {Acta of Bioengineering and Biomechanics}, volume = {23}, number = {3}, pages = {1 -17}, abstract = {Analgesic treatment with diclofenac deteriorates bone structure and decreases biomechanical properties. This bone loss has been though to be reversed by training. The impact of exercise on bone treated with diclofenac (DF) has reminded elusive. In the present study, we assayed the combined impact of exercises and DF on mouse femur. Methods: The femur samples we obtained from 30 days treated C57BL/6J female mice. The training group ran on a horizontal treadmill at 12 m/min by 30 min a day (5% grade/slope). The group of ten mice treated with DF received the drug subcutaneously every day (5 mg/kg of body weight/day). The combined group ran on the treadmill and obtained DF. After 30 days, we sacrificed mice and studied their femurs using microcomputed tomography (μCT), dynamic mechanical analysis (DMA) and nanoindentation. Results: We observed that treadmill running and DF decreased trabecular bone volume and mineral density. Combined effect of training and DF was not additive. A significant interaction of both parameters suggested protective effect of training on bone loss provoked by DF. The femur cortical bone shell remained untouched by the training and treatment. The training and the DF treatment did not alter the storage modulus E significantly. The unchanged storage modulus would be suggesting on the unaltered bone strength. Conclusions: We concluded that even relatively short time of training with concomitant DF treatment could be protective on trabecular bone. Although viscoelastic properties of the entire femur were not modulated, femur trabecular tissue was thinned by treatment with DF and protected by training.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Analgesic treatment with diclofenac deteriorates bone structure and decreases biomechanical properties. This bone loss has been though to be reversed by training. The impact of exercise on bone treated with diclofenac (DF) has reminded elusive. In the present study, we assayed the combined impact of exercises and DF on mouse femur. Methods: The femur samples we obtained from 30 days treated C57BL/6J female mice. The training group ran on a horizontal treadmill at 12 m/min by 30 min a day (5% grade/slope). The group of ten mice treated with DF received the drug subcutaneously every day (5 mg/kg of body weight/day). The combined group ran on the treadmill and obtained DF. After 30 days, we sacrificed mice and studied their femurs using microcomputed tomography (μCT), dynamic mechanical analysis (DMA) and nanoindentation. Results: We observed that treadmill running and DF decreased trabecular bone volume and mineral density. Combined effect of training and DF was not additive. A significant interaction of both parameters suggested protective effect of training on bone loss provoked by DF. The femur cortical bone shell remained untouched by the training and treatment. The training and the DF treatment did not alter the storage modulus E significantly. The unchanged storage modulus would be suggesting on the unaltered bone strength. Conclusions: We concluded that even relatively short time of training with concomitant DF treatment could be protective on trabecular bone. Although viscoelastic properties of the entire femur were not modulated, femur trabecular tissue was thinned by treatment with DF and protected by training. |
1. | Nandan K. P. Babu, Aleksandra Trzaskowska, Piotr Graczyk, Grzegorz Centała, Szymon Mieszczak, Hubert Głowiński, Miłosz Zdunek, Sławomir Mielcarek, Jarosław W. Kłos Nano Lett., 21 (2), pp. 946-951, 2021. @article{doi:10.1021/acs.nanolett.0c03692, title = {The Interaction between Surface Acoustic Waves and Spin Waves: The Role of Anisotropy and Spatial Profiles of the Modes}, author = {Nandan K. P. Babu and Aleksandra Trzaskowska and Piotr Graczyk and Grzegorz Centała and Szymon Mieszczak and Hubert Głowiński and Miłosz Zdunek and Sławomir Mielcarek and Jarosław W. Kłos}, url = {https://doi.org/10.1021/acs.nanolett.0c03692}, doi = {10.1021/acs.nanolett.0c03692}, year = {2021}, date = {2021-01-01}, journal = {Nano Lett.}, volume = {21}, number = {2}, pages = {946-951}, abstract = {The interaction between different types of wave excitation in hybrid systems is usually anisotropic. Magnetoelastic coupling between surface acoustic waves and spin waves strongly depends on the direction of the external magnetic field. However, in the present study we observe that even if the orientation of the field is supportive for the coupling, the magnetoelastic interaction can be significantly reduced for surface acoustic waves with a particular profile in the direction normal to the surface at distances much smaller than the wavelength. We use Brillouin light scattering for the investigation of thermally excited phonons and magnons in a magnetostrictive CoFeB/Au multilayer deposited on a Si substrate. The experimental data are interpreted on the basis of a linearized model of interaction between surface acoustic waves and spin waves.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The interaction between different types of wave excitation in hybrid systems is usually anisotropic. Magnetoelastic coupling between surface acoustic waves and spin waves strongly depends on the direction of the external magnetic field. However, in the present study we observe that even if the orientation of the field is supportive for the coupling, the magnetoelastic interaction can be significantly reduced for surface acoustic waves with a particular profile in the direction normal to the surface at distances much smaller than the wavelength. We use Brillouin light scattering for the investigation of thermally excited phonons and magnons in a magnetostrictive CoFeB/Au multilayer deposited on a Si substrate. The experimental data are interpreted on the basis of a linearized model of interaction between surface acoustic waves and spin waves. |