Studi sifat struktur dan sifat listrik material perovskite LaFe1-xTixO3 ( x = 0.4, 0.5, 0.6 ) = Study of structure and electrical properties of material perovskite LaFe1-xTixO3 ( x = 0.4, 0.5, 0.6 ) / Dedy Yushari Jufri