Magnetic and dielectric properties of $(1-x)$BiFeO$_{3}$–$x$YMnO$_{3}$ multiferroics

Magnetic hysteresis loops obtained in the fields from 0 to $\pm$ 2.5 kOe and dielectric permittivity $\varepsilon$ (at 1 kHz, 1 MHz, and 8.3 GHz) of $(1-x)$BiFeO$_{3}$–$x$YMnO$_{3}$ composite multiferroics (0 $\le x \le$ 0.5) were studied. Ceramic samples of solid solutions were made by the nitrate process. Compositions $(1-x)$BiFeO$_{3}$–$x$YMnO$_{3}$ with 0.1 $\le x \le$ 0.5 were found to be soft ferromagnetic materials sensitive to weak magnetic fields. Coercive field $H_c$ is about 20–32 Oe for these samples. The maximal magnetization was observed in the sample having $x$ = 0.35. For the samples with 0 $\le x \le$ 0.4 at $T$ = 300 K, the permittivity was $\varepsilon\sim$ 17.6–248.6 at the frequency of 1 kHz, 7.8–63.2 at 1 MHz, and 4 $\pm$ 0.3 at 8.3 GHz.