FERROMAGNETISM IN THE ICOSAHEDRAL AL62.5B7.5PD15FE15 QUASI-CRYSTAL

We have found a new magnetic icosahedral quasicrystal, Al62.5B7.5Pd15F e15, in which iron has a magnetic moment. The quasicrystal exhibits fe rromagnetic properties. Its Curie temperature is about 305 K and its c oercive forces at 5 and 300 K are determined to be 1.2 kOe and 40 Oe, respectively. Mossbauer measurements reveal that only about 12% of the Fe atoms have a magnetic moment, and at 4.2 K the average hyperfine m agnetic field at the Fe nuclei is [H-hf] =95.5 kOe. The values of the magnetic moments per Fe atom estimated from the [H-hf] value and from the magnetization value are mu(Fe)= 0.67 mu(B) and 1.63 mu(B), respect ively. This discrepancy may be attributed to the participation of Pd a toms in the magnetic properties of this i-QC. The formation of bonding between Fe and B is thought to be mainly responsible for the creation of the local moment at Fe.