Magnetic ordering and slow dynamics in a Ho-based bulk metallic glass with moderate random magnetic anisotropy

Abstract

Results of magnetic measurements are presented for a Ho-based bulk metallic glass, which shows similarities and differences with conventional spin glasses (SGs), and significant differences with weak random magnetic anisotropy (RMA) systems. Both ac and dc magnetic measurements indicate a single transition from paramagnetic to speromagnetic or spin glasslike state around 5.6 K. The moderate RMA prevents the formation of long- (or quasilong)-range magnetic order and slows down the spin dynamics in the critical region. Further its isothermal remnant magnetization exhibits a small maximum, instead of a gradual increase with field in SGs. The roles of RMA in the magnetic structure and dynamics of disordered and frustrated systems are discussed by comparisons between the weak RMA system, the moderate or strong RMA system, and conventional SG.