Magnetic response of FeRh to static and dynamic disorder
arXiv:1911.11256 · doi:10.1039/D0RA01410A
Abstract
Changes of the magnetic and crystal structure on the microscopic scale in 40 nm FeRh thin films have been applied to investigate the phenomena of a disorder induced ferromagnetism at room temperature initiated through light ion-irradiation with fluences up to 0.125 Ne/nm. Magnetometry shows an increase of magnetic ordering at low temperatures and a decrease of the transition temperature combined with a broadening of the hysteresis with rising ion fluence. Fe Mössbauer spectroscopy reveals the occurrence of an additional magnetic contributions with an hyperfine splitting of 27.2 T - identical to that of ferromagnetic B2-FeRh. The appearance of an anti-site Fe-contribution can be assumed to be lower than 0.6 Fe-at%, indicating that no change of the chemical composition is evident. The investigation of the local structure shows an increase of the static mean square relative displacement determined by X-ray absorption fine structure spectroscopy, while an increase of the defect-concentration has been determined by positron annihilation spectroscopy. From the changes of the microscopic magnetic structure a similarity between the temperature induced and the structural disorder induced ferromagnetic phase can be observed. These findings emphasize the relationship between magnetic ordering and the microscopic defect structure in FeRh.
arXiv comment28 pages 5 pages
References in corpus (9)
- Room-temperature antiferromagnetic memory resistor
- Mastering hysteresis in magnetocaloric materials
- Impact of lattice dynamics on the phase stability of metamagnetic FeRh: Bulk and thin films
- Strain-induced structural instability in FeRh
- Reversible and magnetically unassisted voltage-driven switching of magnetization in FeRh/PMN-PT
- Revealing the Hidden Structural Phases of FeRh
- Optical investigation of magneto-structural phase transition in FeRh
- Tailoring Magnetic Frustration in Strained Epitaxial FeRh Films
- Modulating the phase transition temperature of giant magnetocaloric thin films by ion irradiation