We have used temperature-dependent impedance spectroscopy to study the dielectric response of thin films of ferromagnetic and ferroelectric (Bi 0.9La 0.1) 2NiMnO 6 oxide. This technique has allowed us to disentangle its intrinsic dielectric response and extract the dielectric permittivity of ∼220, which is in close agreement with bulk values but significantly smaller than early reported values for similar thin films. The permittivity is found to be temperature independent in the vicinity of the ferromagnetic transition temperature and independent of magnetic field. We have shown that the measured magnetocapacitance arises from the magnetoresistance of the films, thus indicating a negligible magnetoelectric coupling in these double perovskites, probably due to the different energy scales and mechanisms of ferroelectric and magnetic order. © 2012 American Physical Society.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 8 Aug 2012|