Single diameter modulation effects on Ni nanowire array magnetization reversal

Autor: Costa Arzuza, Luis Carlos, 1983, Pirota, Kleber Roberto, 1973, Béron, Fanny, 1980
Přispěvatelé: UNIVERSIDADE ESTADUAL DE CAMPINAS
Rok vydání: 2021
Předmět:
Zdroj: Repositório da Produção Científica e Intelectual da Unicamp
Universidade Estadual de Campinas (UNICAMP)
instacron:UNICAMP
Repositório Institucional da Unicamp
Popis: Agradecimentos: This research was funded by the Brazilian agencies Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) grant numbers #2017/10581-1 and #2020/07397-7, by the Coordenação de Aperfeiçoamento Pessoal do Nível Superior - Brasil (CAPES) (Finance Code 001), by the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) under Project #436573/2018-0, and the International Research Staff Exchange Scheme (IRSES) - FP7, project COEF-MAGNANO. Spanish Ministerio de Ciencia e Innovación (MICINN) and Research Agency State (AEI), under research project nº PID2019-108075RB-C32, are also gratefully acknowledged. We acknowledge the Brazilian Nanotechnology National Laboratory (LNNano/CNPEM/MCTIC) for the experimental support with the use of the SEM microscope FEI Inspect F-50 Figh Resolution. The authors would like to acknowledge the technical support supplied by the Scientific-Technical services of the University of Oviedo. Finally, we thank Rafael Morales (Universidad del País Vasco/Euskal Herriko Unibertsitatea - UPV/EHU) for funding the travel expenses, Peterson G. de Carvalho (Universidade Estadual de Campinas - UNICAMP) for helpful discussions, and Javier García (University of Oviedo) for the critical reading of this manuscript. Abstract: Geometrically modulated magnetic nanowires are a simple yet efficient strategy to modify the magnetic domain wall propagation since a simple diameter modulation can achieve its pinning during the nanowire magnetization reversal. However, in dense systems of parallel nanowires, the stray fields arising at the diameter interface can interfere with the domain wall propagation in the neighboring nanowires. Therefore, the magnetic behavior of diameter-modulated nanowire arrays can be quite complex and depending on both short and long-range interaction fields, as well as the nanowire geometric dimensions. We applied the first-order reversal curve (FORC) method to bi-segmented Ni nanowire arrays varying the wide segment (45-65 nm diameter, 2.5-10.0 mu m length). The FORC results indicate a magnetic behavior modification depending on its length/diameter aspect ratio. The distributions either exhibit a strong extension along the coercivity axis or a main distribution finishing by a fork feature, whereas the extension greatly reduces in amplitude. With the help of micromagnetic simulations, we propose that a low aspect ratio stabilizes pinned domain walls at the diameter modulation during the magnetization reversal. In this case, long-range axial interaction fields nucleate a domain wall at the nanowire extremities, while short-range ones could induce a nucleation at the diameter interface. However, regardless of the wide segment aspect ratio, the magnetization reversal is governed by the local radial stray fields of the modulation near null magnetization. Our findings demonstrate the capacity of distinguishing between complex magnetic behaviors involving convoluted interaction fields FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPES CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQ Aberto
Databáze: OpenAIRE
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