Doctoral research progress evaluation Academic year

[Audio] The slides presented above are my educational background, research publications, instrument training, academics, and internship experiences. In the second year of my Ph.D. program, I have published two research papers and completed training on various instruments such as pulsed laser deposition, electron beam evaporator, and scanning probe microscope. I also taught physics to undergraduate students and participated in evaluating their bachelor's thesis presentations. In the third year, I plan to participate in a research internship and continue my research on bismuth ferrite. I will also receive training on piezo response force microscopy and cryogenic-free electrical transport option measurement. My research focuses on characterizing the structural properties of bismuth ferrite using x-ray diffraction and other techniques. I have found that the material exhibits a crystalline structure, which is consistent with previous studies. I am excited about the opportunities ahead and look forward to contributing to the field of materials science..

[Audio] Fabrication of Ti and TiO2 buffer layers on various substrates will enable the growth of high-quality Bismuth Ferrite (B-F-O--) films. This planned activity includes the fabrication of Yttrium ferrite (YFeO3, Y-F-O--) buffer layers on Ti/Si and TiO2/Si substrates, as well as on Al2O3 and MgO substrates. The subsequent characterization of these films using 10-ray photoelectron spectroscopy (X-P-S--), 10-ray diffraction (X-R-D--), Raman spectroscopy, vacuum-vacuum atomic spectroscopy (V-VASE), scanning electron microscopy (S-E-M--), atomic force microscopy (A-F-M--), magnetic force microscopy (M-F-M--), and vibrating sample magnetometry (V-S-M--) will provide valuable insights into their structural, chemical, optical, and magnetic properties. These findings will ultimately inform the optimization of B-F-O film deposition parameters for room-temperature memory applications..

[Audio] =====. SDE. Research Publications Instrument training Academics Internship.

[Audio] The objectives of this short thesis are to develop multiferroic thin B-F-O films, fabricate BFO/Ti/Si and BFO/TiO2/Si heterostructures, optimize B-F-O film crystallization quality, and comprehensively characterize the films' properties. The goal is to assess the magnetic behavior and determine the surface composition of the films, ultimately evaluating their potential for memory applications..

[Audio] The fabrication process involves immersing substrates in a piranha solution to remove organics and particulates, followed by dipping in a diluted hydrofluoric acid solution to remove the oxide layer. The substrates are then rinsed with deionized water and dried with nitrogen gas. In the vacuum chamber, the Ar gas is introduced to create a stable environment for sputtering, with a sputtering pressure set to 1.5 × 10⁻³ mbar. The Ø2” Ti and TiO₂ targets are used, and the sputtering mechanics involve applying voltage to the targets..

[Audio] The fabrication of thin B-F-O films through P-L-D involves preparing the substrate and target materials. The substrate is attached to a sample holder using silver-based paint, heated to 120 degrees celsius to remove solvents and prevent contamination, and then mounted onto a laser heater mount. The target material is ground with abrasive paper to remove previous deposition tracks and ensure consistent results, and then mounted onto a carousel target mount. The P-L-D chamber is evacuated to a pressure of 4.8 × 10⁻⁸ mbar, and the distance between the target and substrate is set to 55 millimeters. The laser is aligned at a 45 degrees angle with a spot size of approximately 1.07 millimeters², and the energy entering the chamber is adjusted to achieve the desired laser fluence. Oxygen gas is introduced, and the butterfly valve is adjusted to reach a target background pressure between 0.013–0.13 mbar for each deposition. The substrate is heated to a temperature range of 450–640 degrees celsius using an IR heating laser, with the temperature monitored by a pyrometer. The laser is fired at a 5 Hz repetition rate with 10400 pulses, and the sample is gradually cooled to room temperature in the process gas by turning off the heater. The chamber is then vented, and the sample is removed from the P-L-D system..

[Audio] The crystalline structure of several sets of B-F-O samples was confirmed using a Rigaku SmartLab 3 kilowatt diffractometer. The comparison of B-F-O film results with the reference pattern of the B-F-O target showed optimal conditions for the deposition of B-F-O thin films, resulting in a rhombohedral single-phase structure. Outside these optimal conditions, no crystalline structure was obtained, even with post-annealing. Within the optimal range, a small amount of Bi₂O₃ was detected due to excess Bi in the target. However, no secondary perovskite phases were observed. The detection of the reference B-F-O phase confirms the successful deposition of B-F-O thin films, validating their composition and contributing to their properties such as ferroelectricity and weak ferromagnetism..

[Audio] The S-E-M and A-F-M images display the morphology and topography of various B-F-O samples grown on diverse substrates. The outcomes demonstrate that the selection of substrate substantially influences the development of B-F-O films. On Ti/Si, uniform, dense, larger, rounded grains with higher roughness and random orientation are acquired, whereas on TiO₂/Si, large, more columnar grains with high roughness and more oriented growth pattern are produced. The influence of PO₂ and TS on the growth of B-F-O films is also examined, revealing that higher PO₂ and TS result in better crystalline growth and larger grains. These discoveries offer valuable insights into the optimization of B-F-O film growth procedures..

[Audio] Slide 18: A research internship is planned for the upcoming years of the doctoral program. Slide 17: Lists of courses and academic activities in which I have participated. Slide 16: List of Instruments I have trained on. Slide 7: Description of research publications..

[Audio] The instrument training I received includes using the 10-ray Photoelectron Spectroscopy Kratos Analytical, which enables us to analyze the chemical composition of our samples. This technique is particularly useful for understanding the surface properties of materials, such as the presence of impurities or defects. By examining the 10-P-S spectra, we can determine the elemental composition of our samples and gain insights into their structural and electronic properties..

[Audio] The analysis of film thickness and optical constants using a NIR-UV spectroscopic ellipsometer reveals that the B-F-O film thickness is approximately 35 nanometers, with a roughness layer of around 7 nanometers. The study also highlights the impact of the underlying layer, with TiO2 supporting more uniform and smoother films compared to Ti. This is attributed to TiO2's stability as an oxide layer, promoting uniform film growth, better crystallinity, and fewer defects. In contrast, the Ti layer is less stable and prone to oxidation, leading to greater surface variability and interfacial reactions..

[Audio] Answer: The slides describe my academic activities and research experiences as a second-year Ph.D. student. According to Slide 18, a research internship is planned for the upcoming years of the doctoral program. On Slide 17, I listed the courses and academic activities I have participated in, including teaching physics to undergraduate students and participating in evaluating their bachelor's thesis presentations. Slide 16 shows the list of instruments I have trained on, including pulsed laser deposition, electron beam evaporator, and scanning probe microscope. Finally, Slide 7 provides a description of my research publications and instrument training, including characterizations and key results from my research..

[Audio] Magnetic properties and domain structures of various B-F-O samples were analyzed using a 5-S-M system and an MFM-Bruker Dimension microscope. The analysis revealed that BFO/TiO₂/Si film exhibits lower coercivity and higher remanence compared to BFO/Ti/Si film, indicating easier domain switching and better retention of magnetic alignment. This is attributed to the more aligned grains and domains in the former film. In contrast, the latter film shows higher coercivity and lower remanence, suggesting greater hindrance to domain switching and poor retention of magnetic alignment due to randomly oriented grains and irregular domains..

[Audio] The characterization of BFO/Ti/Si and BFO/TiO₂/Si films showed distinct variations in their structural and magnetic properties. Smaller, randomly oriented grains in BFO/Ti/Si films led to higher coercivity and lower remanent magnetization, whereas larger, columnar grains with better alignment in BFO/TiO₂/Si films resulted in lower coercivity and higher remanent magnetization. This disparity in grain structure and alignment has substantial implications for the suitability of these films for data storage applications..

[Audio] =====. SDE. 2nd year Research Publications Instrument training Academics Internship.

[Audio] Instruments I have been trained on include pulsed laser deposition, electron beam evaporator, magnetron sputtering system, 10-ray photoelectron spectroscopy, scanning probe microscope, Raman spectroscopy, 10-ray powder diffractometer, high-resolution scanning electron microscope, and cryogenic-free vibrating sample magnetometer. Additionally, I am scheduled to receive training in piezo response force microscopy and cryogenic-free electrical transport option measurement system in the near future. These instruments will enable me to conduct advanced research and analysis in my field of study..

[Audio] In my first year of the Ph.D. program, I participated in various courses and academic activities, including academic English for Ph.D. students, Friday seminars at CEITEC BUT, principles of nanoscience and nanotechnologies, advanced topics in nanotechnology, magneto-optical spectroscopy techniques, and spectroscopic methods for non-destructive diagnostics. I also taught physics to undergraduate students at fekt during the summer semester of the 2022/2023 academic year and evaluated their bachelor's thesis presentations under the guidance of Dr Mgr. Dinara Sobolova, Ph.D. Moreover, I attended several seminars and conferences, such as the 1-M-A-P-S Flash 2024 Conference, Advances in Magnetic Resonance International Workshop, A-M-N Seminar Series, fit4nano Workshop, STUDENT EEICT Conference, 10-P-S seminar, production of electronic devices based on thin films seminar, A-L-D for depositing films on complex geometries seminar, and another A-M-N Seminar Series. This experience has enabled me to establish a solid foundation in my field and broaden my understanding in various areas..

[Audio] In my doctoral program, a research internship is planned for the upcoming years, providing valuable hands-on experience and opportunities to apply theoretical knowledge in real-world settings..

[Audio] This year, I will focus on documenting the results of my second-year research for publication, while also investigating the electrical transport, leakage behavior, and piezoelectric domains of BFO/Ti/Si and BFO/TiO₂/Si heterostructures using various characterization techniques. I will utilize optimal conditions from previous research to fabricate new heterostructures and characterize their properties..

[Audio] As a researcher, I have had the opportunity to participate in various academic activities and courses throughout my academic journey. These include research publications, instrument training, teaching, and internship experiences. My research focuses on the development of novel materials and devices, and I have contributed to several publications in reputable scientific journals. I would like to express my gratitude to CEITEC BUT for providing the necessary resources and facilities for this research. I also acknowledge the financial support received from the CzechNanoLab project LM2023051 funded by meys CR. I would like to extend my appreciation to my supervisor, doc. Ing. Vlasta Sedláková, PH D , and co-supervisor, doc. Mgr. Dinara Sobola, Ph.D., for their guidance and support throughout my research..