Выявление магнитной анизотропии в аустенитной хромоникелевой стали после прокатки

Investigations of texture, phase composition and magnetic anisotropy in rolled samples of austenitic steel 09Kh17N5Yu were carried out. It has been shown that the method of magnetic nondestructive testing using measuring of magnetic fields from locally magnetized areas is sensitive to anisotropy of magnetic permeability. Anisotropy of magnetic properties is related to formation of mechanical rolling texture. FCC rolling texture {110}<111> was found in all the rolled samples. Rolling texture, common for BCC structure (strain-induced martensite in low-carbon austenitic steels), developed in the samples with 30% of deformation or higher. Formation of ferromagnetic strain-induced martensite in austenitic steel 09Kh17N5Yu was confirmed by magnetic force microscopy.

Unraveling Dissipation-Related Features in Magnetic Imaging by Bimodal Magnetic Force Microscopy

Magnetic Force Microscopy (MFM) is the principal characterization technique for the study of low-dimensional magnetic materials. Nonetheless, during years, the samples under study was limited to samples in the field of data storage, such as longitudinal hard disk, thin films, or patterned nanostructures. Nowadays, thanks to the advances and developments in the MFM modes and instrumentation, other fields are emerging like skyrmionic structures, 2D materials or biological samples. However, in these experiments artifacts in the magnetic images can have strong impact and need to be carefully verified for a correct interpretation of the results. For that reason, in this paper we will explore new ideas combining the multifrequency modes with the information obtained from the experimental dissipation of energy associated to tip-sample interactions.

Magnetic Force Microscopy on Nanofibers—Limits and Possible Approaches for Randomly Oriented Nanofiber Mats

Magnetic force microscopy (MFM) belongs to the methods that enable spatially resolved magnetization measurements on common thin-film samples or magnetic nanostructures. The lateral resolution can be much higher than in Kerr microscopy, another spatially resolved magnetization imaging technique, but since MFM commonly necessitates positioning a cantilever tip typically within a few nanometers from the surface, it is often more complicated than other techniques. Here, we investigate the progresses in MFM on magnetic nanofibers that can be found in the literature during the last years. While MFM measurements on magnetic nanodots or thin-film samples can often be found in the scientific literature, reports on magnetic force microscopy on single nanofibers or chaotic nanofiber mats are scarce. The aim of this review is to show which MFM investigations can be conducted on magnetic nanofibers, where the recent borders are, and which ideas can be transferred from MFM on other rough surfaces towards nanofiber mats.

Skyrmion Formation in Nanodisks Using Magnetic Force Microscopy Tip

We demonstrated numerically the skyrmion formation in ultrathin nanodisks using a magnetic force microscopy tip. We found that the local magnetic field generated by the magnetic tip significantly affects the magnetization state of the nanodisks and leads to the formation of skyrmions. Experimentally, we confirmed the influence of the local field on the magnetization states of the disks. Micromagnetic simulations explain the evolution of the magnetic state during magnetic force microscopy scanning and confirm the possibility of skyrmion formation. The formation of the horseshoe magnetic domain is a key transition from random labyrinth domain states into the skyrmion state. We showed that the formation of skyrmions by the magnetic probe is a reliable and repetitive procedure. Our findings provide a simple solution for skyrmion formation in nanodisks.

A Ti/Pt/Co Multilayer Stack for Transfer Function Based Magnetic Force Microscopy Calibrations

Magnetic force microscopy (MFM) is a widespread technique for imaging magnetic structures with a resolution of some 10 nanometers. MFM can be calibrated to obtain quantitative (qMFM) spatially resolved magnetization data in units of A/m by determining the calibrated point spread function of the instrument, its instrument calibration function (ICF), from a measurement of a well-known reference sample. Beyond quantifying the MFM data, a deconvolution of the MFM image data with the ICF also corrects the smearing caused by the finite width of the MFM tip stray field distribution. However, the quality of the calibration depends critically on the calculability of the magnetization distribution of the reference sample. Here, we discuss a Ti/Pt/Co multilayer stack that shows a stripe domain pattern as a suitable reference material. A precise control of the fabrication process, combined with a characterization of the sample micromagnetic parameters, allows reliable calculation of the sample’s magnetic stray field, proven by a very good agreement between micromagnetic simulations and qMFM measurements. A calibrated qMFM measurement using the Ti/Pt/Co stack as a reference sample is shown and validated, and the application area for quantitative MFM measurements calibrated with the Ti/Pt/Co stack is discussed.