Tham khảo tài liệu 'ferroelectrics material aspects part 15', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 480 Ferroelectrics - Material Aspects thin films with a tetragonal structure measured at 80 K Yun et al. 2004 . Recent theoretical calculation showed a polarization of about 100 JC cm2 in a rhombohedral structure as well as about 150 pC cm2 in a tetragonal structure. These values showed a good agreement with the experimental ones Ederer et al. 2006 Ricinschi et al. 2006 . General outline of chemical solution deposition Chemical solution deposition CSD is one of the thin film fabrication methods and it includes spin-coating drying and annealing processes. Precursor solution is deposited onto a substrate by a spin-coating process. After the spin-coating process a film dying process is carried out to evaporate the solvent and decompose metal-organic compounds in the precursor. An amorphous film is obtained at this stage. These processes are repeated several times to obtain a desired film thickness. For the film crystallization an annealing process is carried out. It is usually carried out by a rapid thermal annealing RTA equipment to crystallize and densify the film. Higher heating rate usually decomposes metal organic compounds quickly and then desired oxide films with a higher density can be obtained Schwartz 1997 . There are some advantages for CSD i uniformity of the molecules in precursor solutions and thin films ii control of the film thickness by changing the solution concentration or the coating speed iii control of the composition ratio by mixing solutions iv film fabrication in ambient pressure v synthesis of a non-equilibrium phase by the low-temperature process. However there are some disadvantages for this method i possibility of cracks in a film fabrication process ii contamination which results in a difficulty of the manufacturing process iii films with low-coherency comparing with other thin film fabrication methods such as pulsed laser deposition chemical vapor deposition and molecular beam epitaxy. Precursor solutions for BiFeOs Precursor .
