A ferroelectric memory element containing a poly α-amino acid which is a copolymer containing a glutamic acid-γ-ester unit represented by the formula (I):
wherein R1 is a substituted or unsubstituted alkyl group having 1 - 8 carbon atoms, or a benzyl group optionally substituted by a halogen atom, an alkoxy group or a nitro group, and
a glutamic acid-γ-ester unit represented by the formula (II) :
wherein R2 is an unsubstituted alkyl group having 3 - 16 carbon atoms, or an alkyl group having 1 - 6 carbon wherein a part or all of hydrogen atom is substituted by a halogen atom, an alicyclic hydrocarbon group having 3 - 12 carbon atoms, an alkoxy group having 1 - 6 carbon atoms, a cyano group, a phenyl group (a part or all of hydrogen atom is optionally substituted by a halogen atom or an alkoxy group), a phenylalkoxy group (a part or all of hydrogen atom is optionally substituted by a halogen atom or an alkoxy group), or a phenylalkylcarbamate group (a part or all of hydrogen atom is optionally substituted by a halogen atom or an alkoxy group), provided that it is not the same as R1, wherein
the content ratio of the unit of the formula (I) and the unit of the formula (II) ((I)/(II)) is 10/90 - 90/10 in a molar ratio.
一种含有聚
α-氨基酸的
铁电记忆元件,这种聚
α-氨基酸是含有由式 (I) 表示的谷
氨酸-γ-酯单元的共聚物:
其中 R1 是具有 1 - 8 个碳原子的取代或未取代的烷基,或任选被卤素原子、烷氧基或硝基取代的苄基,以及
由式(II)代表的谷
氨酸-γ-酯单元:
其中 R2 是具有 3 - 16 个碳原子的未取代烷基,或具有 1 - 6 个碳原子的烷基,其中部分或全部氢原子被卤素原子取代;具有 3 - 12 个碳原子的脂
环烃基团;具有 1 - 6 个碳原子的烷氧基;
氰基、苯基(部分或全部氢原子任选被卤素原子或烷氧基取代)、苯基烷氧基(部分或全部氢原子任选被卤素原子或烷氧基取代)或苯基烷基
氨基甲酸酯基团(部分或全部氢原子任选被卤素原子或烷氧基取代),条件是它与 R1 不相同,其中
式(I)单元与式(II)单元的摩尔比((I)/(II))为 10/90 - 90/10。