抄録
An accurate measuring system of electrical resistivity has been designed and constructed, and has been applied to determination of transition temperatures in quenched γ-phase Mn–Ni alloys containing 16.5 to 20.5 at%Ni. The Néel temperature as well as the fcc to fct (c/a>1) structure transformation temperature is detectable, and a small change in electrical resistivity due to an orthorhombic distortion is also detected. The magnetic and crystallographic phase diagram for the Mn–Ni alloy system was found to be well confirmed.