Premartensitic effects in near equiatomic TiNi have been pointed out by
several authors(1-5). These include anomalous contrast in electron
microscopy images (mottling, striations, etc. ),diffraction effects(diffuse
streaks, extra reflections, etc.), a resistivity peak above
Ms (temperature at which a perceptible amount of
martensite is formed without applied stress). However the structural changes
occuring in this temperature range are not well understood. The purpose of
this study is to clarify these phenomena.