CONDUCTIVITY MODIFICATIONS OF CALCIUM-DOPED YTTRIUM-IRON-GARNET BY SWIFT HEAVY-ION IRRADIATIONS

We have studied the conductivity modifications, due to swift heavy ion irradiations of epitaxial films of Ca2+-doped yttrium iron garnet (YIG:Ca) having different resistivities. The room temperature film resistivity variation versus fluence exhibited a saturation near 10(7) OMEGA cm, regardless of the pristine sample resistivity ranging between 10(4) and 10(9) OMEGA cm. The amorphization cross sections were also measured from Rutherford backscattering channeling spectrometry data, for values of the electronic energy loss ranging between 7 and 49 MeV mum-1, above the track formation threshold of this material. No significant deviations were found with respect to the undoped YIG data, for the same energy loss values.