X-ray tomography improves the detection of topological charges

A research has improved the detection of topological charges in 3D magnetic memories, which will replace the traditional hard drives. The topological defects (small magnetic eddies), identified in this study by means of X-ray tomography, play a key role in the propagation of information in a fast and stable way.

The article, published in “Nature Communications“, uses a new imaging technique developed through a collaboration between the University of Oviedo, the Nanomaterials and Nanotechnology Research Center (CINN), the Alba Synchrotron and the University of Glasgow.

Photo: From left to right: in the upper row Carlos Quirós, Aurelio Hierro y María Vélez; in the lower row, José María Alameda, Luis Álvarez Prado y José Ignacio Martín.

There is a great interest in this topic at a time when the scientific community and the magnetic recording industry are working on the development of 3D magnetic memories with greater storage capacity than 2D hard drives and in which the defects Magnetic topologies play a key role in spreading information quickly and stably. X-ray magnetic tomography makes it possible to extend the usual magnetic microscopy techniques, which provide images in two dimensions, to the third dimension, creating three-dimensional maps like the one shown in the figure.

The use of the X-ray microscope of the Mistral line of the ALBA Synchrotron, originally designed for tomography of biological samples, was critical in this research. In this work, the measurement method has been adapted to obtain magnetic characterization on a microscopic scale with vectorial and three-dimensional information, the necessary calibration and reconstruction software has been developed and, finally, it has been possible to experimentally identify the three-dimensional configuration and the topological charge of Bloch points.

Article reference: Nature Communications (2020)11:638