Magnetic ‘microflowers’ improve native magnetic fields

A flower-shaped construction only some micrometers in measurement fabricated from a nickel-iron alloy can focus and domestically improve magnetic fields. The scale of the impact could be managed by various the geometry and variety of “petals.”

This magnetic metamaterial, developed by Dr. Anna Palau’s group on the Institut de Ciencia de Supplies de Barcelona (ICMAB) in collaboration together with her companions of the CHIST-ERA MetaMagIC venture, has now been studied at BESSY II in collaboration with Dr. Sergio Valencia.

Such a tool can be utilized to extend the sensitivity of magnetic sensors, to cut back the vitality required for creating native magnetic fields, but in addition, on the PEEM experimental station, to review samples underneath a lot increased magnetic fields than at present doable.

Dr. Palau has developed a particular metamaterial that appears like tiny flowers underneath the scanning electron microscope. The petals encompass strips of a ferromagnetic nickel-iron alloy.

The microflowers could be produced in numerous geometries, not solely with completely different inside and outer radii, but in addition with variable numbers and widths of petals. This flower-shaped geometry causes the sphere strains of an exterior magnetic subject to pay attention within the middle of the gadget, leading to a vastly intensified magnetic subject.

The examine is printed within the journal ACS Nano.

Magnetic metamaterials

“Metamaterials are artificially produced supplies with microstructures whose dimensions are smaller than the electromagnetic or thermal waves they’re designed to govern,” explains Palau.

The physicist is engaged on magnetic microstructures that can be utilized in information storage, data processing, biomedicine, catalysis and magnetic sensor know-how. By utilizing these metamaterials, the sensitivity of magnetic sensors could possibly be extremely elevated, because the magnetic subject to be detected can be amplified on the middle of those techniques.

Mapping magnetic domains at BESSY II

Palau, her scholar Aleix Barrera, and Sergio Valencia have now investigated this on the XPEEM experimental station at BESSY II. They positioned a cobalt rod within the middle of varied microflowers as a sensor for the magnetic subject and mapped the magnetic domains contained in the cobalt rod.

“By adjusting the geometric parameters equivalent to form, measurement and variety of petals, the magnetic conduct could be switched and managed,” says Valencia. In consequence, the sensitivity of a magnetoresistive sensor could possibly be elevated by greater than two orders of magnitude.

New choices, additionally for experiments at XPEEM

This innovation opens up new technological choices for enhancing the efficiency of small magnetic sensors and for creating multifunctional magnetic elements. Sooner or later, such microstructures could possibly be used to generate a lot increased magnetic fields domestically, which can be of curiosity for the experimental XPEEM station at BESSY II.

“Our experimental system is a photoemission electron microscope, so magnetic fields deflect the electrons and make the experiments troublesome,” says Valencia. “The utmost magnetic subject we will usually apply for imaging is about 25 millitesla (mT). With the magnetic subject concentrator, the place the sphere is just domestically enhanced, we will simply obtain fields 5 instances increased.”

That is very thrilling as a result of it opens up the opportunity of learning a spread of magnetic techniques underneath situations that haven’t been doable earlier than.