- Dr. Oleksandr Tkach is a researcher at the CICECO - Aveiro Institute of Materials, Department of Materials and Ceramic Engineering, University of Aveiro. He works in the field of Materials Science & Engineering and Solid State Physics. A particular area of his scientific activity is related to oxide electroceramics. Present research interests of Dr. Tkach include the development of thermoelectric and piezoelecric oxide materials and composites for energy harvesting technologies; giant permittivity dielectric oxides for energy storage; nanostructured magnetoelectrics for sensor and electronic applications; and alternative energy efficient concepts for current assisted ceramic sintering.

- Oleksandr Tkach graduated in Microelectronics and Semiconductor Devices by the National Technical University of Ukraine “Kyiv Polytechnic Institute” in June 1999, investigating nanocrystalline silicon for optoelectronic applications.
In September 2005 he got his Ph.D. in Materials Science & Engineering from the University of Aveiro, Portugal, studying strontium titanate based ceramics for tunable device applications under a personal PhD grant by Portuguese Foundation for Science and Technology (FCT).
Completion of PhD was followed by an award of Experienced Research position within Marie Curie research training network MULTIMAT to be realized by Dr. Tkach in University of Barcelona. However, being not supported in getting Spanish work visa, he had to return to Aveiro for 1.5 year post-doctoral fellow on multiferroics investigation, participating in EU FP6 STREP project MULTICERAL and European Network of Excellence FAME and contributing to 2 invited talks.
In June 2007 Dr. Tkach won a personal post-doctoral grant by FCT to work in University of Porto on alkali tantalates and other perovskite ceramics and thin films, contributing to 2 FCT I&D projects and to an awarded poster done within bilateral Portugal/Germany project.
In December 2012, he got post-doc contract at the Johannes Gutenberg University of Mainz, Germany, within EU FP7 project IFOX and ERC project MASPIC, investigating artificial multiferroic heterostructures and contributing to the photoemission-electron-microscopy synchrotron beam-times.
In February 2014 Dr. Tkach was promoted to Assistant Researcher position at the University of Aveiro, CICECO, coordinating FCT Independent Researcher project, acknowledged in his 25 papers, 6 book chapters and 5 invited talks and used for hiring 2 post-doc fellows with Dr. Tkach as a solely supervisor for them as well as for 1 Master student. There are more 4 Master and 1 post-doc co-supervisions by Dr. Tkach. Besides being the project PI, Dr. Tkach participated in COST action TO-BE, 2 FCT I&D projects and 1 project with industry; contributed to organization of 3 scientific events, more 2 invited talks and 1 awarded poster; edited a book published by Nova Science Publishers; joined Editorial boards of Int. J. Mater. Sci. Appl., Nanomater. Sci. Eng. and Coatings, reviewing as well manuscripts for >30 scientific journals.

- Dr. Tkach publication profile contains 1 edited book, 6 book chapters and 82 articles, including high impact factor (IF) Nature Physics (IF=19.256), Advanced Functional Materials (IF=16.836), Chemistry of Materials (IF=9.567) and Carbon (IF=8.821). From his 39 publications in the top quartile JCR SCI journals in their areas, 6 papers are published in the highest IF journal of specific area Materials Science - Ceramics (J. Eur. Ceram. Soc.) and 5 in the area Metallurgy and Metallurgical Engineering (Acta Mater.), as well as more 8 in the top 5 journals of their areas. 2 publications by Dr. Tkach in J. Eur. Ceram. Soc. 37 (2017) 2391 and Coatings 8 (2018) 449 were highlighted as the feature articles, while 1 more paper in J. Mater. Chem. C 6 (2018) 2467 has been selected for the themed collection: 2018 Journal of Materials Chemistry C HOT Papers. Dr. Tkach is first author, lead writer, and principal contributor on 43/3 and corresponding author on 25/3 papers/chapters.

The main fields of the published research are related to SrTiO₃-based materials (53 papers, 4 book chapters and PhD thesis), alkali tantalates and niobates (13 papers and 2 book chapters), magnetoelectric heterostructures (10 papers) and graphene oxide derived materials (5 papers).

According to Scopus database (Author ID: 7006368460), his papers are cited ca. 1500 times (over 1200 without self-citations) with h-index of 23 to date (Sept. 2020). According to Google Scholar (profile Alexander Tkach), there are over 1750 citations with h-index of 25.