Three-state dual spin valve structure

A dual spin valve is built with exchange bias on the top and bottom pinned layers and a central free layer. By suitable choice of the antiferromagnetic and ferromagnetic layer thicknesses, it is possible to separate the three magnetization switching fields and produce a staircase magnetoresistive curve. The maximum magnetoresistance (MR) ratio is 7.6% for current-perpendicular-to-plane and 6.3% for current-in-plane geometries with intermediate MRs of 3.9% and 3.0%, respectively. The use of exchange bias in a multistate memory device is discussed

Negative magnetoresistance in dual spin valve structures with a synthetic antiferromagnetic free layer

peer-reviewedGiant magnetoresistance (GMR) in spin valves is due to spin-dependent scattering occurring at ferromagnet/normal metal (F/N) interfaces and/or in the ferromagnetic layers. In a spin valve with a typical F/N/F structure where the spin scattering asymmetry factor (alpha) of both F/N interfaces is the same (more or less than 1), the GMR is expected to be positive. If alpha is greater than one at one F/N interface and less than one at the other F/N interface, however, the GMR is expected to be negative. Here, we show that the F1/Cu/SAF/Cu/F2/IrMn dual spin valve structure exhibits negative GMR, where F1 and F2 are CoFe and SAF = CoFe/Ru t/CoFe, due to both opposite electron spin scattering asymmetry factor at the CoFe/Ru/CoFe interfaces as well as the electrical separation of the overall structure into two GMR spin valves connected in parallel. A GMR of 6% is observed in the structure without the Ru spacer layer, insertion of a 0.6 nm thick Ru in the SAF results in a negative GMR ratio of -3% , which becomes positive again at the Ru thickness of 0.8 nm, the oscillation from positive to negative MR is consistent with interlayer exchange coupling period across the Ru spacer

Pattering data from NPVE software for Helium Ion Microscopy (HIM) irradiation data

Pattering data from NPVE software for Helium Ion Microscopy (HIM) irradiation dat

Inverted magnetoresistance in dual spin valve structures with a synthetic antiferromagnetic free layer

We report an oscillation of the giant magnetoresistance GMR ratio as a function of Ru layer thickness in the CoFe/Cu/ CoFe/Ru/CoFe SAF/Cu/CoFe/IrMn dual spin valve SV structure. A normal GMR with a positive sign is observed for the thickness of Ru providing a ferromagnetic interlayer exchange coupling IEC . The inverted GMR is observed for the thickness of Ru providing an antiferromagnetic IEC, which is consistent with IEC period across the Ru spacer as well as the electrical separation of the overall structure into two SVs connected in parallel

Perpendicular Magnetic Anisotropy in CoFeB/Pd Bilayers

Perpendicular magnetic anisotropy is observed in ultrathin (0.6 nm) amorphous Co40Fe40B20 when sputtered on an MgO (001) buffer layer and capped with Pd. The layers are superparamagnetic with a blocking temperature of similar to 230 K, below which they show an exponential temperature dependence of coercivity. Perpendicular magnetic anisotropy is observed in the as-deposited state and the mechanism is different from that of CoFeB/Pt, which requires postannealing. These ultrathin layers could be a model system for studies of electric field effects on magnetic anisotropy

Data publication: Coherent coupling of metamaterial resonators with dipole transitions of boron acceptors in Si

FTIR transmission spectra of the samples at various temperature

Magnetization dynamics and mutual spin-pumping in SAFs

Primary data related to the publication in PRB: Article Link. Pre-release version is available at: Arxiv, ResearchGate. Some of the file are auxiliary or analisys files for faster display of the main results (like .opj, .ods files). Main raw data files are in the archives

Data publication: Impedimetric Nanobiosensor for the Detection of SARS-CoV-2 Antigens and Antibodies

This publication includes datasets of electrical impedance spectroscopy measurements of the response of functionalized gold nanowires when interacting with antigens and antibodies related to SARS-CoV-2 in physiological conditions and in human plasma samples