A PARALLEL-MOTION VIBRATING-SAMPLE HARMONIC MAGNETOMETER

A new type of high-sensitivity vibrating-sample magnetometer (VSM) use ful for measurements of soft and hard magnetic materials is described. This instrument differs from the Foner type in the vibration system, which is a bar vibrating at its resonance frequency. Additionally, the electronic control preserves a constant vibration amplitude and versi ons with parallel and/or perpendicular motion can be designed. Magneti c moments as small as 5 x 10(-8) A m2 have been detected at room tempe rature and the overall accuracy is better than 0.5% using the simple p rototype presented here. An instrument with this system is easy to con struct, relatively inexpensive and, due to its versatility, it could b e a useful tool for research, industry and teaching purposes.