Liquid sample holder for optimal fluid magnetic measurements

Magnetic fluids have been the subject of intense research for several decades due to their numerous applications and for their fundamental science. Commercial magnetometers are accurate and well-characterized for solid and powder samples, but artifacts can occur in magnetic measurements of fluid samples. These measurement artifacts originate primarily from the dynamic nature of the sample center position, size, shape, and particle distribution. Here, we present a sample holder design that minimizes the motion of the fluid sample during measurement, significantly reducing these measurement artifacts. We also discuss additional considerations in the design to minimize magnetic signals from the sample holder itself, such as the choice of the sample holder material and shape. Experimental data demonstrating the effectiveness of the new design, including background signal, are presented.