title: Statistical properties of Barkhausen noise in amorphous ferromagnetic films.
abstract: We investigate the statistical properties of the Barkhausen noise in amorphous ferromagnetic films with thicknesses in the range between 100 and 1000 nm. From Barkhausen noise time series measured with the traditional inductive technique, we perform a wide statistical analysis and establish the scaling exponents τ,α,1/σνz, and ϑ. We also focus on the average shape of the avalanches, which gives further indications on the domain-wall dynamics. Based on experimental results, we group the amorphous films in a single universality class, characterized by scaling exponents τ=1.28±0.02,α=1.52±0.3, and 1/σνz=ϑ=1.83±0.03, values compatible with that obtained for several bulk amorphous magnetic materials. Besides, we verify that the avalanche shape depends on the universality class. By considering the theoretical models for the dynamics of a ferromagnetic domain wall driven by an external magnetic field through a disordered medium found in literature, we interpret the results and identify an experimental evidence that these amorphous films, within this thickness range, present a typical three-dimensional magnetic behavior with predominant short-range elastic interactions governing the domain-wall dynamics. Moreover, we provide experimental support for the validity of a general scaling form for the average avalanche shape for non-mean-field systems.
authors.affiliation: Departamento de Física Teórica e Experimental, Universidade Federal do Rio Grande do Norte, 59078-970 Natal, RN, Brazil.
authors.forename: F
authors.initials: F
authors.lastname: Bohn
authors.affiliation: Departamento de Física Teórica e Experimental, Universidade Federal do Rio Grande do Norte, 59078-970 Natal, RN, Brazil.
authors.forename: M A
authors.initials: MA
authors.lastname: Corrêa
authors.affiliation: Departamento de Física, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil.
authors.forename: M
authors.initials: M
authors.lastname: Carara
authors.affiliation: Department of Mechanical Engineering and Materials Science and Department of Physics, Yale University, New Haven, Connecticut 06520-8286, USA.
authors.forename: S
authors.initials: S
authors.lastname: Papanikolaou
authors.affiliation: INRIM, Strada delle Cacce 91, 10135 Torino, Italy and ISI Foundation, Viale S. Severo 65, 10133 Torino, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Durin
authors.affiliation: Centro Brasileiro de Pesquisas Físicas, Rua Dr. Xavier Sigaud 150, Urca, 22290-180 Rio de Janeiro, RJ, Brazil.
authors.forename: R L
authors.initials: RL
authors.lastname: Sommer
mesh_terms: D004548:Elasticity; D060526:Magnetic Fields; D059346:Magnets; D015233:Models, Statistical