Surface modified layer of TiO2 with anatase phase can't be obtained from direct spin-coated TIP on IF (interstitial free) steel by using sol-gel techniques. Thus, this study used interlayers (Fe atoms diffusion barriers) not only to inhibit Fe atoms of the substrates from diffusing to out surface but also to fix surface modified layer of TiO2. Middle layers adopted two different ways: (1) Dry process adopted sputtered Cr thin films. (2) Wet process adopted spin-coated method with TOES gel to obtain Si-O thin films after calcined. This research observed the diffusion abilities of Fe atoms in...