A hall sensing magnetometer for measuring magnetization, anisotropy, rotational loss and time effects

A Hall element magnetometer which senses flux from a sample is arranged so that it is unaffected by an applied field. The instrument is used to investigate magnetization, anisotropy, rotational loss and time effects. The magnetometer is compact and requires no moving parts other than sample rotation when measuring anisotropy or rotational loss. Studies made thus far with the magnetometer include magnetic properties of recording tape, thin films, amorphous ribbon, transformer and motor laminations and bulk material. The instrument has the capability of sensing loss as a function of applied field, magnetization, time, rotation frequency or the number of rotations in a field. An output similar to that from a torque magnetometer can be recorded against rotation angle. Curves of magnetization against field may be measured using either dc or ac fields. For several sample and probe configurations a sensitivity of at least 10^-5emu has been achieved at fields up to 10 oersteds.