This thematic issue introduces the latest research results in materials science, including the analysis of the possibilities of application of high entropy alloys for hydrogen storage, properties of piezoceramics and ferroelectric, corrosion behaviour of structural materials, and investigation of functional thin films' properties and synthesis technologies and the optical properties of gallium arsenide nanoparticles obtained by laser ablation in liquid acetone. The presented edition will be useful to a wide range of specialists in materials science both at the theoretical and practical levels.