Intermediate phases produced during the icosahedral-crystal transition

An investigation of a new quasicrystalline phase obtained in an alloy of Al₈₆Mn₁₄ under slow solidification rate is carried out. It has been named the N phase and seems to correspond to a transition phase between the T phase and the crystalline state. Its diffraction pattern shows an elliptical arrangement of 10 spots in a pseudo-fivefold direction and a threefold diffraction pattern similar to the one reported in the Al₄Mn phase. This result indicates that, depending on the solidification rate, different quasicrystalline phases are obtained. Therefore, the transition between the icosahedral and the crystalline states could give rise to different phases as in a continuous transition.