EFFECTS OF COMPOSITION AND SUBSTRATE-TEMPERATURE ON THE AC PROPERTIESOF COEVAPORATED MN SIOX THIN-FILMS/

Capacitance, a.c, conductance and loss factor have been measured in Cu -Mn/SiOx-Cu sandwich structures with compositions 1, 3, 5 and 10 at% M n in the frequency range 10-10(6) Hz between temperatures of 110 and 5 00 K. The capacitance has a weak minim um at 1.0 MHz for all temperatu res, whilst the a.c. conductance increases between four and eight orde rs of magnitude for temperatures of 150 and 473 K, respectively. Vario us a.c. conduction models have been considered, and it has been conclu ded that correlated barrier hopping best describes the results. The Go swami-Goswami model was used to describe the variation of loss factor with temperature and composition.