Thermophysical properties of hydrogenated vanadium-doped magnesium porous nanostructures.

Vanadium-doped magnesium nanostructures are fabricated by an oblique angle co-deposition method and hydrogenated/dehydrogenated for 21 cycles. The effective thermal conductivity and density of the MgH2 nanostructures is measured by using a photothermal system. A multilayer physical model is used to fit the experimental data. Our results show that the effective thermal conductivity of the hydrogenated V-doped Mg nanostructures is in the range of 1.16-2.40 W m(-1) K(-1) and the density falls in the range of 878-1320 kg m(-3). The measured density agrees well with the estimation from electron micrograph observation. Variation in the measurements indicates strong nonuniformity of the sample structure and thickness. Based on the measured density and effective thermal conductivity, the thermal conductivity of bulk V-doped Mg hydrides is also evaluated using Maxwell's correlation.