Thermal stability of microstructure and mechanical properties of Ni/Ru multilayers

Phase formation of B2-RuAl during annealing of Ru/Al multilayers

“…No distinct satellite peaks are observed due to the presence of L-disorder. Nevertheless, the ability to simulate the diffraction patterns of the MLs with L < 4.5 nm, indicates that Ru and Al grow by coherent epitaxy on each other, similar to the Ru/Ni MLs with L < 20 nm [19]. The calculated superlattice periods are close to the nominal ones.…”

“…The standard deviations of both hA k i and the fraction of intergranular space are relatively big, despite the large number of grains/voids analyzed, as the corresponding distributions are quite broad and asymmetric. In addition, the SEM micrographs suggest that the intergranular channels become not only larger but also deeper with increasing L. Growth of columns, perpendicular to the substrate, was also observed in Ni/Ru [19], Ag/ Cu [25], Ni 80 Fe 20 /Cu [26], NiFe/Ag [27] as well as Co/Cu [28] MLs, for example. The width of the columns close to the surface increases from 18 AE 5 nm for the [Ru 1 nm/Al 1.24 nm] 80 ML to 50 AE 12 nm for the MLs with L !…”

“…Both crystallographic planes are the planes with largest in-plane atomic densities and are most commonly formed during physical vapor deposition. For example, Wen et al [19] observed a growth of the Ru layers along the (0001) direction in Ni/Ru MLs. Correspondingly, the d-spacings of the Al and Ru layers in these simulations were taken equal to d (111) Al ¼ 0.234 nm [20] and d (0002) Ru ¼ 0.214 nm [21], respectively.…”

Amorphous-CuTa/amorphous-CoZrNb multilayers: Structure, mechanical properties and thermal stability

“…Considerable efforts have been focused on the structure and mechanical properties of c-/c-metal multilayers as a function of thermal annealing [11][12][13][14]. Mara et al [13] prepared the Cu/Nb multilayer and found that the tensile strength decreased when temperature increasing due to the grain growth.…”

“…Mara et al [13] prepared the Cu/Nb multilayer and found that the tensile strength decreased when temperature increasing due to the grain growth. Wen et al [14] prepared Ni/Ru multilayers and observed a significant drop in hardness when annealing at 600°C due to the breakdown of periodic structure. Besides interfacial intermixing and degradation of periodic structure, for a-/a-multilayers, thermal annealing could also stimulate structure relaxation and crystallization of amorphous layers [15][16][17], all of which may result in the evolution of mechanical properties, including elastic modulus and hardness.…”