  Magnetization, magnetoresistance, and magnetodielectric measurements have
been carried out on the half doped charge ordered manganite, Pr_0.5Ca_0.5MnO_3.
The low temperature state is found to be strongly dependent on the oxygen
stoichiometry whereas the high temperature state remains almost unaltered. A
disorder driven phase separation in the low temperature state is noticed in the
magnetic, magnetoresistance, and dielectric measurements which is attributed to
the oxygen deficiency in the compound. A considerable magnetodielectric (MD)
effect is noticed close to room temperature at 280 K which is fascinating for
technological applications. The strongest MD effect observed in between 180 K
and 200 K is found to be uncorrelated with magnetoresistance but it is
suggested to be due to a number of intricate processes occuring in this
temperature range which includes paramagnetic to antiferromagnetic transition,
incommensurate to commensurate charge ordering and orbital ordering. The
strongest MD effect seems to emerge from the high sensitivity of the
incommensurate state to the external perturbation such as external magnetic
field. The results propose the possible magnetoelectric coupling in the charge
ordered compound.
