Magnetic domain configurations of pulsed laser deposited MnBi hard magnetic films

Hard magnetic MnBi films were obtained by appropriate heat treatments of pulsed laser deposited (PLD) (Bi/Mn) films. X-ray diffraction patterns indicated a slight texture of MnBi crystallites and magnetometry measurements showed a slight preferential growth of the crystallites with their c-axis perp...

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Detalles Bibliográficos
Autores: Madurga Pérez, Vicente, Favieres Ruiz, Cristina, Vergara Platero, José
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2022
País:España
Institución:Universidad Pública de Navarra
Repositorio:Academica-e. Repositorio Institucional de la Universidad Pública de Navarra
OAI Identifier:oai:academica-e.unavarra.es:2454/44586
Acceso en línea:https://hdl.handle.net/2454/44586
Access Level:acceso abierto
Palabra clave:Rare-earth free permanent magnets
MnBi hard magnetic films
Magnetic domain configuration
Perpendicular anisotropy
Pulsed laser deposition
Descripción
Sumario:Hard magnetic MnBi films were obtained by appropriate heat treatments of pulsed laser deposited (PLD) (Bi/Mn) films. X-ray diffraction patterns indicated a slight texture of MnBi crystallites and magnetometry measurements showed a slight preferential growth of the crystallites with their c-axis perpendicular to the film plane. Magnetic force microscopy (MFM) measurements displayed the presence of magnetic domains, whose size was in the micrometer range, and which were correlated to the MnBi grains observed in the sample. The addition of extra Mn layers did not modify significantly the previous structural and magnetic results. Nevertheless, the size of the magnetic domains increased to a few microns. However, on adding extra Bi layers, upon annealing, the MnBi grains grew with their c-axes perpendicular to the film plane. A perpendicular to the film magnetic anisotropy was deduced from the hysteresis loops, where an increase in the remanence of the magnetization was measured when the magnetic field was applied perpendicular to the film plane. In these samples, by measuring the magnetic domain configuration of the samples by MFM, we observed that the size of the magnetic domains exceeded the dimensions of the grains. This change in the magnetic structure of the films was assumed to be due to the coupling of the magnetization in the neighboring grains, and it was responsible for the decrease of the coercivity in the Bi rich samples.