Standardization of a quantitative Magneto-Optical Indicator Film based magnetic field measurement technique

Access to markets that demand quality-assured magnetic materials has been constrained by gaps in the ranges of options for reliably characterising micro-magnetic materials. Manufacturers of electrotechnical products and developers of nanotechnologies could choose to use quantitative Magneto-Optical Indicator film measurement (qMOIF), a fast, high-resolution imaging technique, that suits samples sized up to several centimetres squared and rough samples. The method works in harsh environments and does not require costly and time-consuming surface treatments.

While commercial offerings perform well within limited ranges of scale; a size gap in provision exists: only flat samples can be measured at sized at about 100 nm and only accurately at centimetre-scale, whereas industrial magnetic materials tend to be in the millimetre or centimetre range and have rough rather than flat surfaces.

The NanoMag project validated qMOIF techniques to the micro-metre and nanometre-scale, but a gap remains at the microscale, prompting the International Electrotechnical Commission (IEC) to request industrially relevant specifications on the use of qMOIF.

The project has defined and developed guidance on the best use of a new standardised qMOIF method for characterising micro-magnetic materials, to be presented as a best practice guide on fast and reliable measurements from the micro- to millimetre scale for industry.

A Technical Specification will be submitted to the IEC as a sub-document to its existing standard, then its uptake promoted to potential end-users.

Subsequently, for the first time, standardised measurements of magnetic fields will be viable for macroscopic objects down to nanoscale features, opening up opportunities for developing smaller, faster and higher-performing magnetic sensor and magnetic materials. This will present innovation opportunities, for example in the automotive sector and for high-quality electrical steel sheets as used in generators and transformers for low-loss electrical energy conversion.