Signature of weak ferroelectricity and ferromagnetism in Mn doped CuO nanostructures

Weak ferroelectricity and ferromagnetism have been observed in Cu_1−xMn_xO (x=0, 0.03, 0.05, 0.07) nanostructures synthesized by the hydrothermal method. The X-ray diffraction analysis indicates that Mn substituted at Cu site in the CuO lattice and confirms the single phase formation for all samples. Polarization verses electric field (P–E) loops show lossy capacitor behavior for all the samples; however the value of polarization decreases by Mn doping. The dielectric constant and loss tangent is found maximum for pure CuO sample and decreases with Mn content. Room temperature magnetization versus magnetic field (M–H) loops indicate the existence of ferromagnetism in pure and x=0.03 samples. Further, paramagnetic behavior is observed for x=0.05 and 0.07 samples. The coexistence of both magnetic and ferroelectric order is found for Cu_1−xMn_xO (x=0.03) sample, however, no magnetoelectric coupling is observed at room temperature