Välkommen is Swedish and means “welcome”. Our latest product comes from Sweden. Since July of this year, we represent DynoMag, a room temperature AC-susceptometer from our new partner Acreo in Sweden. The compact system is easy to use. It features a wide frequency range, outstanding sensitivity and can be used for measurements on solid, liquid or powdery samples.
AC-susceptometry measures the performance of the sample in the alternating magnetic field. Different processes may occur in the magnetic field. If nano particles are suspended in liquid, the particles may spin with the alternating field as long as they are composed of a single magnetic domain and are thermally blocked. This is referred to as Brown relaxation.
On the other hand, if not the entire particle spins, but the magnetic spin flips with the alternating field, this is called Néel relaxation. This and other dynamic processes are depicted in AC-susceptibility measurements.
Where Brown relaxation is the main mechanism, measurements will also contain information on the particle size, which allows drawing conclusions on the particle distribution.
This information can easily be gained with the integrated software. A log-normal distribution is fitted to the measured data. The left image in Fig. 1 shows a print screen of the software with measurement data. The image on the right shows the fitted particle size distribution.
Application fields are the characterization of magnetic nano particles regarding their size and size distribution, time-dependent analyses of particle stability or the clustering of nano particles and the temporal analysis of biomolecule attachment. In geophysics, with samples including magnetic particles, AC-susceptometry is used for soil analysis.
So who wants to say the Swedes can only do furniture...