Chemical mechanisms in electroless deposition

Morphology, Thermal Stability, and Solderability of Electroless Nickel–phosphorus Plating Layer

“…Between these two atoms, the diffusion rate of P is relatively small compared to that of Ni. 10 Hence, EN-P coating having higher amounts of P involves the movement of more P atoms from a given area per unit time during deposition to achieve segregation of Ni and P. 11 As mentioned before, the general EN-P coating layer contains approximately 10 wt.% P. Since the required P segregation is very large, it prevents the nucleation of face-centered-cubic (FCC) Ni phase which results in an amorphous structure in the as-deposited condition. Other investigators also confirmed the amorphous nature of EN-P coatings with high P content (>7 wt.% P) in its as-deposited condition.…”

Effect of boron content in electroless Ni–B layer on plating layer properties and soldering characteristics with Sn–Ag solder

“…The mechanism of EN-B plating suggests that during EN-B deposition, B atoms are randomly captured on Ni atoms and that the variation in the rate of segregation of Ni and B atoms determines the crystal-structure of the resultant coating. The diffusion rate of the B atom is relatively small compared to that of the Ni atom [30]. Hence, an EN-B coating with a higher B content allows the movement during deposition of more B atoms from a given area per unit time to achieve segregation of Ni and B [31].…”

Subsurface hydrogen exciton‐like states in solid catalysts

“…This exciton-like surface hydrogen-vacancy state is not the same as the surface exciton that occurs for semiconductors [15 to 171 ; our proposed hydrogen-vacancy state has a high degree of delocalization and a low internal binding energy. It can form weak bonds with surface species, as is implied experimentally in autocatalytic processes [18]. Overlap of exciton-like surface states creates a new level near to E,, with consequent charge transfer which causes the Fermi level to shift to slightly higher energy (Fig.…”