Magnetic Properties and Phase Stability of Icosahedral Al–Pd–Mn–B Quasicrystals

The magnetic properties and the effect of B content on the appearance of ferromagnetism, as well as the phase stability of the icosahedral phase, were examined for the icosahedral Al_{70- x} Pd₁₅Mn₁₅B _x (x=0 to 6 at.%) alloys. As the B content increases freezing temperature (T _f) and ferromagnetic Curie temperature (Θ_f) increase markedly accompanying the drastic increase in M increase the transition of the magnetic nature of Mn from paramagnetism to ferromagnetism. The phase diagram between the transition temperature of each magnetic state and B content was constructed. The ferromagnetic state was obtained in the B range above 3 at.% B at temperature between 480 K and 550 K. It is thus concluded that the replacement of Al by B causes a drastic change in the magnetic properties though the change in magnetic interaction of Mn–Mn pair and creation and Mn–B pairs.