Highlights

Scientists in the University of Nebraska MRSEC are using very short light pulses from a femtosecond laser to perturb magnetic materials and to probe their behavior at times after the perturbation. The light pulses are only about 100 millionth-billionths of a second long. By adjusting the delay time between the pump and probe pulses, we get a detailed picture of how the magnetization precesses with time. These investigations provide information that is useful in such applications as magnetic information storage on hard disk drives.

Researchers of the MRSEC at the University of Nebraska offer a different route to control the magnetism by electric fields. In a recent article published in Physical Review Letters, they predict that it is possible to change the magnetization at the interface between ferromagnetic and ferroelectric materials by reversing the electric polarization of the ferroelectric. The origin of this phenomenon is the change in the bonding strength at the ferroelectric/ferromagnet interface due ferroelectric displacements altering the interface magnetization when the electric polarization reverses.

Magnetocrystalline anisotropy is found in many magnetic materials which means that the energy of a magnet depends on the magnetization direction. This keeps our windshield wipers moving and our toy magnets attached to the fridge. However, on changing the direction of the field that aligns the magnetic moments, the aligned magnetization normally remains nearly unchanged. […]

Anisotropic magnetoresistance (AMR) is the difference in the resistivity of ferromagnetic materials in external magnetic field when the field is applied along or perpendicular to the current. In macroscopic materials the conductance is diffusive (the mean free path of the electron is much smaller than the device dimensions) and AMR is due to spin dependent […]