CRITICAL BEHAVIOUR OF AMORPHOUS FERROMAGNETIC MATERIALS WITH MAGNETIC BISTABILITY

The criticality of magnetic Instability in amorphous materials of different shapes : wires, ribbons and microwires is discussed. Temperature and field dependences of velocity of domain wall propagation has been measured in the range of temperatures 5-300 K in amorphous Fe₆₅B₁₅Si₁₅C₅ microwires. Domain wall velocity within the experimental range of magnetic fields (65-100 A/m) and temperatures are between 35 and 65 m/s. Domain wall mobility was estimated from these dependences. The value of critical field for domain wall propagation is lower than the switching field reflecting the existance of an energy barrier for domain wall to be depinned or critical size of reversed domain. Common characteristic features of switching in both bistable magnetic materials and domain-wall junctions are discussed.