Analysis of Sorption and Desorption Characteristics of Nanolaminated Nb/Zr Systems

Hydrogen sorption and desorption in Zr and Nb monolayer coatings and in nanolaminated Nb/Zr systems with individual layers of different thicknesses were studied. The coatings obtained by magnetron sputtering were subjected to hydrogenation at 350°C and 10 atm. Hydrogen absorption was analyzed using kinetic curves, while desorption was studied using thermal desorption spectroscopy. It was found that the maximum hydrogen content was achieved in the system with individual layers 50 nm thick. This is due to the optimal ratio of Nb/Zr interphase boundaries and the volume of the zirconium layer, which contributes to efficient hydrogen accumulation. With a decrease in the layer thickness to 25 and 10 nm, an increase in the number of interphase boundaries does not lead to an increase in sorption capacity due to the limited volume of zirconium. In samples 100 nm thick, the sorption capacity decreases, which is due to a decrease in the proportion of interfaces and slowdown in hydrogen. diffusion. Analysis of thermal desorption curves showed that the hydrogen release temperature depends on the layer thickness. In the thermal desorption spectra, the peak shifts to the low-temperature region with increasing heating rate, which is associated with dynamic changes in hydrogen trap states and a decrease in internal stresses. This leads to upward hydrogen diffusion. The obtained results demonstrate the possibility of targeted control of hydrogen sorption and desorption by optimizing the architecture of multilayer systems. This opens up prospects for the development of functional coatings and thin-film hydrogen storage materials with adjustable characteristics.