Hysteresis Loop Tracer for Thin Films in Ultrahigh Vacuum

The hysteresis loop tracer described in this paper has two unique features: first, the pickup coil leaves one face of the film exposed thus allowing the film to be deposited while the pickup coil is in place; secondly, the high sensitivity (noise equivalent to 5×10−13 Wb) allows measurements to be made on very thin films or on films having a very small saturation magnetization. The construction of the hysteresis loop tracer is discussed in detail and its effectiveness evaluated.