Low-field microwave magnetoabsorption in manganites

We report the magnetic field dependence of microwave absorption at low fields (200 Oe), in thin film and bulk samples of La1-xBa xMnO3-z. We demonstrate, using a very simple cavity configuration, that the magnetic field sensitivity of the microwave response of the giant magnetoresistance materials offers possibilities of using such materials in devices operating at low fields. Low-field dc magnetization and ac resistivity measurements are also presented.© 1996 American Institute of Physics.