Magnetoelectric and magnetodielectric properties of (1−x)Ba0.6Sr0.4TiO3–(x)La0.7Ca0.3MnO3 composites

We have investigated the magnetoelectric and magnetodielectric properties of (1−x)Ba0.6Sr0.4TiO3–(x)La0.7Ca0.3MnO3 composites, where constituent Ba0.6Sr0.4TiO3 and La0.7Ca0.3MnO3 have nearly the same ferroelectric ( T C E ∼ 270 K ) and ferromagnetic ( T C M ∼ 275 K ) Curie temperatures. Below a percolation-limit sample, i.e.,  x = 0.05 , we have observed a decrease of electrical polarization and an increase of dielectric constant with strong frequency dependences near T C M when we turn on the magnet. On the other hand, we have observed little change of electrical polarization and a decrease of dielectric constant without frequency dependences at 10 K. We have attributed the observed magnetoelectric and magnetodielectric properties to the extrinsic magnetoresistance origin near T C M and to the strain-induced magnetoelectric coupling at 10 K.