THURSDAY, Feb. 1, 12 p.m. 11 FLOOR OF THE GAMOW TOWER
John Moreland
Magnetics Group: Electromagnetics Division: Electronic and Electrical Engineering Laboratory
National Institute of Standards and Technology: United States Department of Commerce
Microelectromechanical Systems for Metrology: Applications in Nanomagnetism
I will review some of the novel methods for measuring ferromagnetic properties of thin films based on micromechanical magnetometers and put them into context relative to current research on nanomagnetism. Measurements rely on the detection of mechanical forces or torques on thin films deposited onto microcantilevers. Displacements of the cantilever are detected by optical methods similar to those developed for atomic force microscopy (AFM). High sensitivities are achieved by integrating the sample with the detector, allowing magnetic measurements of samples with a total magnetic moment smaller than that detectable with conventional magnetometers. Cantilevers with low spring constants and high mechanical Q are essential for these measurements. Sensitivities better than 10^5 Bohr magnetons are possible at room temperature.