pradheesh

Dear all, In order to prepare LaFeO3 (sol-gel method) I used ferric nitrate as the starting product without noticing it to be a hygroscopic material. If I use ferric nitrate should I heat it at some temperature before weighing it? Also if I use Fe3O4 which acid can be used for dissolving it? Is there any alternate material for Fe which can be used for sol-gel synthesis? Am a Physics graduate and I am unaware of the chemistry involved. Pradheesh