The distinction between the magnetic properties of quasicrystalline and amorphous Al sub 85-x Pd sub 15 Mn sub x alloys

• Published in: Journal of physics. Condensed matter Vol. 6; no. 46; pp. 10129 - 10140
• Main Authors: Hattori, Y, Fukamichi, K, Chikama, H, Aruga-Katori, H, Goto, T
• Format: Journal Article
• Language: English
• Published: 14.11.1994
• ISSN: 0953-8984

Quasicrystalline and amorphous Al sub 85-x Pd sub 15 Mn sub x (x=12, 13, 14 and 15) alloys have been prepared by rapid melt quenching and high-rate DC sputtering. The saturation magnetic moment M sub s , the magnetic manganese atom ratio, the magnetic moment per magnetic Mn atom P sub c and spin glass behavior have been investigated for both these phases. The temperature dependence of DC magnetic susceptibility for these quasicrystalline and amorphous alloys follows a Curie-Weiss law over a wide temperature range. The value of M sub s and the average magnetic moment per Mn atom (P sub c ) for the quasicrystalline alloys are much smaller than those for the amorphous alloys. The magnetic Mn atom ratio in the quasicrystalline phase is approx10%, being almost half that that in the amorphous phase in a similar manner to the Al sub 80-x Cu sub 20 Mn sub x (x=13, 14 and 15) alloy system. The Mn concentration dependence of P sub c in the quasicrystalline phase is steeper than that in the amorphous phase, and the value of P sub c of the quasicrystalline Al sub 70 Pd sub 15 Mn sub 15 alloy exceeds t mu sub beta of a bare moment of Mn. It is, therefore, considered that a giant moment is formed by polarization of 4d electrons of palladium in the quasicrystalline alloy. The present alloys in both phases are magnetically dilute alloys and spin glass behavior has been observed. The spin freezing temperature T sub f for the quasicrystalline phase is lower than those for the amorphous phase in accordance with the smaller Mn atom ratio. From these results, a marked difference in the magnetic properties between the quasicrystalline and amorphous phases has been confirmed, reflecting their different local atomic structure.