利用原子力显微镜改变P(VDF/TrFE)聚合物分子链偶极子极性实现数据存储的读/写/擦除/改写

包括读、写、擦除和改写等信息存储现象的产生是由于在外加电压的作用下，铁电体“聚偏二氟乙烯-三氟胸苷”异分子聚合物的分子链偶极子的极性发生了变化．为达此目的，使原子力显微镜工作在压电响应模式下，它比传统的数据存储方法要有优势．将20nm厚的“聚偏二氟乙烯-三氟胸苷”薄膜放置于原子力显微镜的导电悬臂梁触针和石墨基片之间，直流电通过AFM触针在几微秒的时间内极化铁电畴，同时用交流电来辨识这些纳米尺度(约60nm)的铁电畴，这些铁电畴的尺寸由外加电压的大小和持续时间等参数来决定，可以实现约19．2Gb／cm^2(120Gb／in^2)的数据存储．

Switching the Molecular Chain's Dipoles for Data Storage to Write/Read/Erase/Rewrite in P(VDF/TrFE) Copolymer Using AFM

A small probe voltage was applied to a ferroelectric ultra-thin polymer film and resulted in the storage of a memory bit. The explanation of this write/read/erase/rewrite data storage phenomenon is based on switching molecular chain's dipoles of the ferroelectric polyvinylidene fluoride-trifluoroethylene P (VDF/TrFE) copolymer under an applied voltage. For this purpose, the use of the Atomic Force Microscopy (AFM) in piezoresponse mode, seems to have an advantage over the classic methods for data storage. A twenty nanometer (20 nm) film thickness of P(VDF/TrFE) was sandwiched between the conductive AFM cantilever tip and the graphite substrate. The applied DC voltage through the AFM tip polarized the ferroelectric domains in few milliseconds while the applied AC voltage read them in nano-scale size as 60 nm.The dimension of the nano-domains depends on certain parameters such as the magnitude and the duration of the applied voltage. Therefore, data storage of about 19.2 Gb / cm2 ( 120 Gb/in2 ) could be achieved.