respected researcher, 

recently i examine the pelletised powder sample( rare earth doped BiFeO3)in PE loop tracer under room temperature the Pmax is 0.352micro coloumb / cm2. then i pool the sample magnetically in helmholz coil, such that the mag. lines of forces passing perpendicular to the sample at the field of 9kOe for 25 min. then, i examin the same in PE loop tracer at room temperature, the polarization reduces of 0.236 microcolumb / cm2. why there is reduction in polarization? whether the sample is coupled with magnetic and electric field. please help me to sort this issue.

thanks in advance