  Resistive and capacitive switching in capacitor metal/nanocomposite/metal
(M/NC/M) structures based on (CoFeB)x(LiNbO3)100-x NC fabricated by ion-beam
sputtering with metal content x $\approx$ 8-20 at. % is studied. The
peculiarity of the structure synthesis was the use of increased oxygen content
($\approx$ 2*10^-5 Torr) at the initial stage of the NC growth. The NC films,
along with metal nanogranules of 3-6 nm in size, contained a large number of
dispersed Co (Fe) atoms (up to ~10^22 cm^-3). Measurements were performed both
in DC and AC (frequency range 5-13 MHz) regimes. When switching structures from
high-resistance (Roff) to low-resistance (Ron) state, the effect of a strong
increase in their capacity was found, which reaches 8 times at x $\approx$ 15
at. % and the resistance ratio Roff/Ron $\approx$ 40. The effect is explained
by the synergetic combination of the multifilamentary character of resistive
switching (RS) and structural features of the samples associated, in
particular, with the formation of high-resistance and strongly polarizable
LiNbO3 layer near the bottom electrode of the structures. The proposed model is
confirmed by investigations of RS of two-layer nanoscale M/NC/LiNbO3/M
structures as well as by studies of the magnetization of M/NC/M structures in
the pristine state and after RS.
