Solid-state amorphization between thin films of two pure crystalline metals that have a negative heat of mixing is shown by Schwartz. An isothermal anneal is used to amorphize a binary crystalline structure via interdiffusion of one species, preferentially into the other. We report a metallic-glass formation by solid state amorphization in a Ni/Ti multilayered structure by low temperature annealing in the electron microscope. TEM allows us to view the composition modulation and interfaces of the Ni/Ti multilayered structure in crossection. Crossectional TEM is regularly used to view the composition modulation and interfaces of thin films. A TEM fitted with a hot-stage sample holder makes it possible to heat the cross-sectioned multilayer in-situ and record the ensuing reaction at the Ni-Ti interfaces.Ni/Ti multilayers with a period of 26 nm (55 at.pct. Ni) were fabricated by magnetron sputtering, the details and parameters are outlined elsewhere. TEM specimens were prepared for cross-section viewing with a technique similar to Bravman and Sinclair, in combination with encapsulating the epoxied pieces with in a metal tube as described by Newcomb, et al.