The interfacial diffusion between Ni-Zn-Cu ferrite and Ag during sintering, at temperatures ranging from 850 to 950C, was investigated by using the scanning electron microscopy energy-dispersive X-ray analysis technique. It was found that the diffusion increased with increasing sintering temperature. Impurities in the ferrite, especially SiO2 and NH4Cl, promoted interfacial diffusion. The interfacial diffusion of Ag could be explained by liquid-phase formation at grain boundaries in sintered ferrite.

T.Nakamura, Y.Okano, S.Miura: Journal of Materials Science, 1998, 33[5], 1091-4