Developing a Kerr Microscope for Upper-Division Solid State Physics Laboratories
Mentor:Hector Mireles, Associate Professor of Physics, Cal Poly Pomona
We have constructed a low-cost Kerr microscope for use in our upper-division solid state laboratory course. We developed the instrument by retrofitting a polarizing microscope, then tested its capacity to image magnetic domains on the surface of polished ferromagnetic samples: Nd-Fe-B and Fe-Si. The instrument serves as a learning platform with which students observe the essential aspects of ferromagnetism, of the magneto-optic Kerr effect, and of magnetic domains. By applying a controlled external magnetic field to the sample, students can observe and manipulate magnetic domains in real time with a digital camera. We offer some technical guidance in the development of a Kerr microscope, and outline some of the learning objectives that undergraduates can achieve by using a Kerr microscope in a formal lab curriculum.