Resolving magnetic contributions in BiFeO3 nanoparticles using First order reversal curves

Author(s)

Cardona-Rodriguez, A. ; Rodriguez, Edwin Ramos ; Carranza-Celis, D. ; Vergara-Duran, N. ; da Cruz, A. S. E. ; Londono, O. Moscoso ; Knobel, M. ; Reiber, A. ; Muraca, Diego ; Ramirez, Juan Gabriel

• Document type: Journal article
• Source: Journal of Magnetism and Magnetic Materials; v. 556, p. 7-pg., 2022-04-29.

Abstract

BiFeO3 (BFO) nanoparticles (NPs) were studied using First-Order Reversal Curve (FORC) and temperaturedependent magnetometry measurements. The BFO NPs were fabricated by a sol-gel method, while the crystal structure and the average particle radius were obtained by powder X-ray diffraction analysis and Small-Angle XRay Scattering (SAXS) measurements, respectively. The NP size varies below and above the typical bulk BFO spin cycloid length (lambda = 62 nm). Below lambda, the NPs show ferromagnetic-like hysteresis loops where the saturation magnetization decreases while nanoparticle size rises. This magnetic behavior changes for NP size over lambda, which only exhibits a paramagnetic contribution. The FORC distributions indicate the presence of two competing sizedependent contributions to the observed magnetic signal Also, the FORC distributions show that in the ferromagnetic regime there are two competing size-dependent contributions to the observed magnetic signal. Our results suggest the existence of a magnetic core-shell structure in NPs below lambda, possibly driven by the strong spin-lattice coupling. (AU)

• FAPESP's process: 20/07397-7 - Control and imaging of interfacial patterned skyrmionic textures in perpendicular magnetic anisotropy multilayer systems
• Grantee: Fanny Béron
• Support Opportunities: Regular Research Grants
• FAPESP's process: 17/10581-1 - Emergent phenomena in reduced dimension systems
• Grantee: Pascoal Jose Giglio Pagliuso
• Support Opportunities: Special Projects