Recently, our group reported, for the first time, the in situ nucleation and growth of Ag NPs on the surface of some silver compounds, such as Ag2WO4, Ag2MoO4 and Ag3PO4, driven by an accelerated electron beam under high vacuum (from an electronic microscope) [1-3]. This phenomenon generates new possibilities of applications, as well as, photocatalyst, sensor and bactericide [4, 5], however, the fundamental physical picture is still unclear, and an understanding the physical transformation on the bulk structure is mandatory. Our aim is to have more elements to understand the driving force and the mechanism for the Ag nucleation and growth process, using neutrons diffraction to probe the bulk of samples irradiated and non-irradiated with electron beam.